diff --git a/src/mudlib/entity.py b/src/mudlib/entity.py
index 7e99bec..f4bc845 100644
--- a/src/mudlib/entity.py
+++ b/src/mudlib/entity.py
@@ -3,9 +3,13 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
+from typing import TYPE_CHECKING
 
 from mudlib.object import Object
 
+if TYPE_CHECKING:
+    from mudlib.npc_schedule import NpcSchedule
+
 
 @dataclass(eq=False)
 class Entity(Object):
@@ -84,4 +88,5 @@ class Mob(Entity):
     behavior_state: str = "idle"
     behavior_data: dict = field(default_factory=dict)
     npc_name: str | None = None  # links to dialogue tree
-    schedule: list | None = None  # for future schedule system
+    schedule: NpcSchedule | None = None  # time-based behavior schedule
+    schedule_last_hour: int | None = None  # last hour schedule was processed
diff --git a/src/mudlib/gametime.py b/src/mudlib/gametime.py
new file mode 100644
index 0000000..7059ce6
--- /dev/null
+++ b/src/mudlib/gametime.py
@@ -0,0 +1,90 @@
+"""Game time system for converting real time to in-game time."""
+
+import time
+
+
+class GameTime:
+    """Tracks game time based on real time with configurable ratio.
+
+    By default: 1 real minute = 1 game hour (24 real minutes = 1 game day).
+    """
+
+    def __init__(self, epoch: float, real_minutes_per_game_hour: float = 1.0):
+        """Initialize game time.
+
+        Args:
+            epoch: Unix timestamp for game time hour 0
+            real_minutes_per_game_hour: Real minutes per game hour (default 1.0)
+        """
+        self.epoch = epoch
+        self.real_minutes_per_game_hour = real_minutes_per_game_hour
+
+    def get_game_hour(self) -> int:
+        """Get current game hour (0-23)."""
+        elapsed_real_seconds = time.time() - self.epoch
+        elapsed_real_minutes = elapsed_real_seconds / 60
+        elapsed_game_hours = elapsed_real_minutes / self.real_minutes_per_game_hour
+        return int(elapsed_game_hours) % 24
+
+    def get_game_time(self) -> tuple[int, int]:
+        """Get current game time as (hour, minute).
+
+        Returns:
+            Tuple of (hour 0-23, minute 0-59)
+        """
+        elapsed_real_seconds = time.time() - self.epoch
+        elapsed_real_minutes = elapsed_real_seconds / 60
+        elapsed_game_hours = elapsed_real_minutes / self.real_minutes_per_game_hour
+
+        hour = int(elapsed_game_hours) % 24
+        minute_fraction = elapsed_game_hours - int(elapsed_game_hours)
+        minute = int(minute_fraction * 60) % 60
+
+        return hour, minute
+
+
+# Global game time instance (initialized at server startup)
+_game_time: GameTime | None = None
+
+
+def init_game_time(
+    epoch: float | None = None, real_minutes_per_game_hour: float = 1.0
+) -> None:
+    """Initialize the global game time instance.
+
+    Args:
+        epoch: Unix timestamp for game time hour 0 (default: current time)
+        real_minutes_per_game_hour: Real minutes per game hour (default 1.0)
+    """
+    global _game_time
+    if epoch is None:
+        epoch = time.time()
+    _game_time = GameTime(epoch, real_minutes_per_game_hour)
+
+
+def get_game_hour() -> int:
+    """Get current game hour from global instance.
+
+    Returns:
+        Current game hour (0-23)
+
+    Raises:
+        RuntimeError: If game time not initialized
+    """
+    if _game_time is None:
+        raise RuntimeError("Game time not initialized. Call init_game_time() first.")
+    return _game_time.get_game_hour()
+
+
+def get_game_time() -> tuple[int, int]:
+    """Get current game time from global instance.
+
+    Returns:
+        Tuple of (hour 0-23, minute 0-59)
+
+    Raises:
+        RuntimeError: If game time not initialized
+    """
+    if _game_time is None:
+        raise RuntimeError("Game time not initialized. Call init_game_time() first.")
+    return _game_time.get_game_time()
diff --git a/src/mudlib/mobs.py b/src/mudlib/mobs.py
index 7f91ce4..31d739e 100644
--- a/src/mudlib/mobs.py
+++ b/src/mudlib/mobs.py
@@ -7,6 +7,7 @@ from pathlib import Path
 
 from mudlib.entity import Mob
 from mudlib.loot import LootEntry
+from mudlib.npc_schedule import NpcSchedule, ScheduleEntry
 from mudlib.zone import Zone
 
 logger = logging.getLogger(__name__)
@@ -23,6 +24,7 @@ class MobTemplate:
     max_stamina: float
     moves: list[str] = field(default_factory=list)
     loot: list[LootEntry] = field(default_factory=list)
+    schedule: NpcSchedule | None = None
 
 
 # Module-level registries
@@ -47,6 +49,35 @@ def load_mob_template(path: Path) -> MobTemplate:
             )
         )
 
+    # Parse schedule if present
+    schedule = None
+    schedule_data = data.get("schedule", [])
+    if schedule_data:
+        entries = []
+        for entry_data in schedule_data:
+            # Extract location if present
+            location = None
+            if "location" in entry_data:
+                location = entry_data["location"]
+
+            # Extract all other fields as data (excluding hour, state, location)
+            data_fields = {
+                k: v
+                for k, v in entry_data.items()
+                if k not in ("hour", "state", "location")
+            }
+            entry_behavior_data = data_fields if data_fields else None
+
+            entries.append(
+                ScheduleEntry(
+                    hour=entry_data["hour"],
+                    state=entry_data["state"],
+                    location=location,
+                    data=entry_behavior_data,
+                )
+            )
+        schedule = NpcSchedule(entries=entries)
+
     return MobTemplate(
         name=data["name"],
         description=data["description"],
@@ -55,6 +86,7 @@ def load_mob_template(path: Path) -> MobTemplate:
         max_stamina=data["max_stamina"],
         moves=data.get("moves", []),
         loot=loot_entries,
+        schedule=schedule,
     )
 
 
@@ -92,6 +124,7 @@ def spawn_mob(
         max_stamina=template.max_stamina,
         description=template.description,
         moves=list(template.moves),
+        schedule=template.schedule,
     )
     if home_region is not None:
         # Validate home_region structure
diff --git a/src/mudlib/npc_schedule.py b/src/mudlib/npc_schedule.py
new file mode 100644
index 0000000..3aa25e8
--- /dev/null
+++ b/src/mudlib/npc_schedule.py
@@ -0,0 +1,101 @@
+"""NPC schedule system for time-based behavior transitions."""
+
+from dataclasses import dataclass
+
+from mudlib.entity import Mob
+from mudlib.npc_behavior import transition_state
+
+
+@dataclass
+class ScheduleEntry:
+    """A single schedule entry for a specific hour."""
+
+    hour: int  # Game hour (0-23) when this entry activates
+    state: str  # Behavior state to transition to
+    location: dict | None = None  # Optional {"x": int, "y": int} to move to
+    data: dict | None = None  # Optional behavior_data to set
+
+
+@dataclass
+class NpcSchedule:
+    """Schedule for an NPC with multiple time-based entries."""
+
+    entries: list[ScheduleEntry]
+
+    def get_active_entry(self, hour: int) -> ScheduleEntry:
+        """Get the schedule entry that should be active at the given hour.
+
+        Returns the most recent entry at or before the given hour,
+        wrapping around midnight if necessary.
+
+        Args:
+            hour: Game hour (0-23)
+
+        Returns:
+            The active ScheduleEntry for this hour
+        """
+        if not self.entries:
+            raise ValueError("Schedule has no entries")
+
+        # Find the most recent entry at or before this hour
+        best_entry = None
+        best_hour = -1
+
+        for entry in self.entries:
+            if entry.hour <= hour and entry.hour > best_hour:
+                best_entry = entry
+                best_hour = entry.hour
+
+        # If no entry found before current hour, wrap around to last entry
+        if best_entry is None:
+            # Find the entry with the highest hour
+            best_entry = max(self.entries, key=lambda e: e.hour)
+
+        return best_entry
+
+
+def process_schedules(mob_list: list[Mob], game_hour: int) -> None:
+    """Process NPC schedules and apply transitions if hour has changed.
+
+    Args:
+        mob_list: List of mobs to process
+        game_hour: Current game hour (0-23)
+    """
+    for mob in mob_list:
+        if not mob.alive:
+            continue
+
+        # Skip mobs in conversation (don't interrupt active player interaction)
+        if mob.behavior_state == "converse":
+            continue
+
+        schedule = mob.schedule
+        if schedule is None or not isinstance(schedule, NpcSchedule):
+            continue
+
+        # Check if we've already processed this hour
+        if mob.schedule_last_hour == game_hour:
+            continue
+
+        # Get the active entry for this hour
+        entry = schedule.get_active_entry(game_hour)
+
+        # Check if anything needs to change
+        needs_state_change = mob.behavior_state != entry.state
+        needs_location_change = entry.location is not None and (
+            mob.x != entry.location["x"] or mob.y != entry.location["y"]
+        )
+        needs_data_change = entry.data is not None
+
+        # Only apply changes if something actually changed
+        if needs_state_change or needs_location_change or needs_data_change:
+            # Transition state (this also sets behavior_data if entry.data is set)
+            transition_state(mob, entry.state, entry.data)
+
+            # Move mob if location specified
+            if entry.location is not None:
+                mob.x = entry.location["x"]
+                mob.y = entry.location["y"]
+
+        # Mark this hour as processed
+        mob.schedule_last_hour = game_hour
diff --git a/src/mudlib/server.py b/src/mudlib/server.py
index f548f1a..fa9e78d 100644
--- a/src/mudlib/server.py
+++ b/src/mudlib/server.py
@@ -37,6 +37,7 @@ from mudlib.combat.engine import process_combat
 from mudlib.content import load_commands
 from mudlib.corpse import process_decomposing
 from mudlib.effects import clear_expired
+from mudlib.gametime import get_game_hour, init_game_time
 from mudlib.gmcp import (
     send_char_status,
     send_char_vitals,
@@ -46,7 +47,8 @@ from mudlib.gmcp import (
 )
 from mudlib.if_session import broadcast_to_spectators
 from mudlib.mob_ai import process_mob_movement, process_mobs
-from mudlib.mobs import load_mob_templates, mob_templates
+from mudlib.mobs import load_mob_templates, mob_templates, mobs
+from mudlib.npc_schedule import process_schedules
 from mudlib.player import Player, players
 from mudlib.prompt import render_prompt
 from mudlib.resting import process_resting
@@ -94,6 +96,7 @@ async def game_loop() -> None:
     log.info("game loop started (%d ticks/sec)", TICK_RATE)
     last_save_time = time.monotonic()
     tick_count = 0
+    last_schedule_hour = -1
 
     while True:
         t0 = asyncio.get_event_loop().time()
@@ -106,6 +109,12 @@ async def game_loop() -> None:
         await process_unconscious()
         await process_decomposing()
 
+        # Process NPC schedules when game hour changes
+        current_hour = get_game_hour()
+        if current_hour != last_schedule_hour:
+            process_schedules(mobs, current_hour)
+            last_schedule_hour = current_hour
+
         # MSDP updates once per second (every TICK_RATE ticks)
         if tick_count % TICK_RATE == 0:
             for p in list(players.values()):
@@ -491,6 +500,10 @@ async def run_server() -> None:
     log.info("initializing database at %s", db_path)
     init_db(db_path)
 
+    # Initialize game time (1 real minute = 1 game hour)
+    init_game_time(real_minutes_per_game_hour=1.0)
+    log.info("game time initialized (1 real minute = 1 game hour)")
+
     # Generate world once at startup (cached to build/ after first run)
     cache_dir = pathlib.Path(__file__).resolve().parents[2] / "build"
     config = load_world_config()
diff --git a/tests/test_npc_schedule.py b/tests/test_npc_schedule.py
new file mode 100644
index 0000000..671ae9f
--- /dev/null
+++ b/tests/test_npc_schedule.py
@@ -0,0 +1,348 @@
+"""Tests for NPC schedule system."""
+
+import time
+from pathlib import Path
+
+import pytest
+
+from mudlib.entity import Mob
+from mudlib.gametime import GameTime, get_game_hour
+from mudlib.mobs import load_mob_template, mob_templates, mobs, spawn_mob
+from mudlib.npc_schedule import (
+    NpcSchedule,
+    ScheduleEntry,
+    process_schedules,
+)
+from mudlib.zone import Zone
+
+
+@pytest.fixture(autouse=True)
+def clear_mobs():
+    """Clear mobs list before and after each test."""
+    mobs.clear()
+    mob_templates.clear()
+    yield
+    mobs.clear()
+    mob_templates.clear()
+
+
+def test_schedule_entry_creation():
+    """ScheduleEntry can be created with required fields."""
+    entry = ScheduleEntry(hour=6, state="working")
+    assert entry.hour == 6
+    assert entry.state == "working"
+    assert entry.location is None
+    assert entry.data is None
+
+
+def test_schedule_entry_with_location():
+    """ScheduleEntry can include optional location."""
+    entry = ScheduleEntry(hour=10, state="patrol", location={"x": 5, "y": 10})
+    assert entry.hour == 10
+    assert entry.state == "patrol"
+    assert entry.location == {"x": 5, "y": 10}
+
+
+def test_schedule_entry_with_data():
+    """ScheduleEntry can include optional behavior data."""
+    waypoints = [{"x": 1, "y": 2}, {"x": 3, "y": 4}]
+    entry = ScheduleEntry(hour=8, state="patrol", data={"waypoints": waypoints})
+    assert entry.hour == 8
+    assert entry.state == "patrol"
+    assert entry.data == {"waypoints": waypoints}
+
+
+def test_npc_schedule_get_active_entry():
+    """NpcSchedule.get_active_entry returns correct entry for a given hour."""
+    entries = [
+        ScheduleEntry(hour=6, state="working"),
+        ScheduleEntry(hour=12, state="idle"),
+        ScheduleEntry(hour=18, state="patrol"),
+    ]
+    schedule = NpcSchedule(entries=entries)
+
+    # At hour 6, return first entry
+    assert schedule.get_active_entry(6).state == "working"
+    # Between entries, return most recent
+    assert schedule.get_active_entry(8).state == "working"
+    assert schedule.get_active_entry(12).state == "idle"
+    assert schedule.get_active_entry(15).state == "idle"
+    assert schedule.get_active_entry(18).state == "patrol"
+    assert schedule.get_active_entry(20).state == "patrol"
+
+
+def test_npc_schedule_wraps_around_midnight():
+    """NpcSchedule.get_active_entry wraps around midnight correctly."""
+    entries = [
+        ScheduleEntry(hour=6, state="working"),
+        ScheduleEntry(hour=22, state="idle"),
+    ]
+    schedule = NpcSchedule(entries=entries)
+
+    # Before first entry, wrap to last entry
+    assert schedule.get_active_entry(0).state == "idle"
+    assert schedule.get_active_entry(2).state == "idle"
+    assert schedule.get_active_entry(5).state == "idle"
+    # After first entry, use it
+    assert schedule.get_active_entry(6).state == "working"
+    assert schedule.get_active_entry(10).state == "working"
+    # After last entry
+    assert schedule.get_active_entry(22).state == "idle"
+    assert schedule.get_active_entry(23).state == "idle"
+
+
+def test_process_schedules_transitions_state(monkeypatch):
+    """process_schedules transitions mob state when hour changes."""
+    zone = Zone(name="test", width=20, height=20)
+    mob = Mob(
+        name="librarian",
+        location=zone,
+        x=5,
+        y=5,
+        behavior_state="idle",
+    )
+    entries = [
+        ScheduleEntry(hour=6, state="working"),
+        ScheduleEntry(hour=18, state="idle"),
+    ]
+    mob.schedule = NpcSchedule(entries=entries)
+    mobs.append(mob)
+
+    # At hour 6, transition to working
+    process_schedules(mobs, 6)
+    assert mob.behavior_state == "working"
+
+    # At hour 18, transition to idle
+    process_schedules(mobs, 18)
+    assert mob.behavior_state == "idle"
+
+
+def test_process_schedules_moves_mob_to_location(monkeypatch):
+    """process_schedules moves mob to scheduled location."""
+    zone = Zone(name="test", width=20, height=20)
+    mob = Mob(
+        name="guard",
+        location=zone,
+        x=0,
+        y=0,
+        behavior_state="idle",
+    )
+    entries = [
+        ScheduleEntry(hour=8, state="patrol", location={"x": 10, "y": 5}),
+    ]
+    mob.schedule = NpcSchedule(entries=entries)
+    mobs.append(mob)
+
+    # Process at hour 8
+    process_schedules(mobs, 8)
+    assert mob.x == 10
+    assert mob.y == 5
+    assert mob.behavior_state == "patrol"
+
+
+def test_process_schedules_sets_behavior_data(monkeypatch):
+    """process_schedules sets behavior_data from schedule entry."""
+    zone = Zone(name="test", width=20, height=20)
+    mob = Mob(
+        name="guard",
+        location=zone,
+        x=0,
+        y=0,
+        behavior_state="idle",
+    )
+    waypoints = [{"x": 1, "y": 2}, {"x": 3, "y": 4}]
+    entries = [
+        ScheduleEntry(hour=10, state="patrol", data={"waypoints": waypoints}),
+    ]
+    mob.schedule = NpcSchedule(entries=entries)
+    mobs.append(mob)
+
+    # Process at hour 10
+    process_schedules(mobs, 10)
+    assert mob.behavior_state == "patrol"
+    # behavior_data includes the schedule data
+    assert mob.behavior_data["waypoints"] == waypoints
+    # last hour is tracked on the mob directly
+    assert mob.schedule_last_hour == 10
+
+
+def test_process_schedules_doesnt_reprocess_same_hour(monkeypatch):
+    """process_schedules doesn't re-process the same hour."""
+    zone = Zone(name="test", width=20, height=20)
+    mob = Mob(
+        name="npc",
+        location=zone,
+        x=0,
+        y=0,
+        behavior_state="idle",
+    )
+    entries = [
+        ScheduleEntry(hour=6, state="working", location={"x": 10, "y": 10}),
+    ]
+    mob.schedule = NpcSchedule(entries=entries)
+    mobs.append(mob)
+
+    # First process at hour 6
+    process_schedules(mobs, 6)
+    assert mob.x == 10
+    assert mob.y == 10
+    assert mob.behavior_state == "working"
+
+    # Move mob away manually
+    mob.x = 5
+    mob.y = 5
+    mob.behavior_state = "idle"
+
+    # Process again at hour 6 (should not re-apply)
+    process_schedules(mobs, 6)
+    assert mob.x == 5  # Should not move back
+    assert mob.y == 5
+    assert mob.behavior_state == "idle"  # Should not transition back
+
+
+def test_game_time_returns_valid_hour():
+    """GameTime.get_game_hour returns hour in range 0-23."""
+    game_time = GameTime(epoch=time.time(), real_minutes_per_game_hour=1.0)
+    hour = game_time.get_game_hour()
+    assert 0 <= hour < 24
+
+
+def test_game_time_advances_correctly():
+    """GameTime advances correctly based on real time."""
+    # Start at a known epoch
+    epoch = time.time()
+    game_time = GameTime(epoch=epoch, real_minutes_per_game_hour=1.0)
+
+    # At epoch, should be hour 0
+    hour_at_epoch = game_time.get_game_hour()
+
+    # Simulate time passing by creating a new GameTime with earlier epoch
+    # (1 minute ago = 1 game hour ago)
+    earlier_epoch = epoch - 60  # 1 minute ago
+    game_time_earlier = GameTime(epoch=earlier_epoch, real_minutes_per_game_hour=1.0)
+    hour_after_one_minute = game_time_earlier.get_game_hour()
+
+    # Hour should have advanced by 1
+    expected_hour = (hour_at_epoch + 1) % 24
+    assert hour_after_one_minute == expected_hour
+
+
+def test_load_schedule_from_toml(tmp_path: Path):
+    """Schedule data can be loaded from mob TOML template."""
+    # Create a temp TOML file with schedule
+    toml_content = """
+name = "librarian"
+description = "a studious librarian"
+pl = 100.0
+stamina = 100.0
+max_stamina = 100.0
+moves = []
+
+[[schedule]]
+hour = 6
+state = "working"
+location = {x = 10, y = 5}
+
+[[schedule]]
+hour = 20
+state = "patrol"
+waypoints = [{x = 10, y = 5}, {x = 12, y = 5}, {x = 12, y = 7}]
+
+[[schedule]]
+hour = 22
+state = "idle"
+"""
+    toml_file = tmp_path / "librarian.toml"
+    toml_file.write_text(toml_content)
+
+    # Load template
+    template = load_mob_template(toml_file)
+    assert template.name == "librarian"
+    assert template.schedule is not None
+    assert len(template.schedule.entries) == 3
+
+    # Check first entry
+    entry1 = template.schedule.entries[0]
+    assert entry1.hour == 6
+    assert entry1.state == "working"
+    assert entry1.location == {"x": 10, "y": 5}
+
+    # Check second entry
+    entry2 = template.schedule.entries[1]
+    assert entry2.hour == 20
+    assert entry2.state == "patrol"
+    assert entry2.data == {
+        "waypoints": [{"x": 10, "y": 5}, {"x": 12, "y": 5}, {"x": 12, "y": 7}]
+    }
+
+    # Check third entry
+    entry3 = template.schedule.entries[2]
+    assert entry3.hour == 22
+    assert entry3.state == "idle"
+
+
+def test_schedule_carries_to_spawned_mob(tmp_path: Path):
+    """Schedule carries through from template to spawned mob."""
+    # Create a temp TOML file with schedule
+    toml_content = """
+name = "guard"
+description = "a watchful guard"
+pl = 100.0
+stamina = 100.0
+max_stamina = 100.0
+moves = []
+
+[[schedule]]
+hour = 8
+state = "patrol"
+location = {x = 5, y = 5}
+"""
+    toml_file = tmp_path / "guard.toml"
+    toml_file.write_text(toml_content)
+
+    # Load template and spawn mob
+    template = load_mob_template(toml_file)
+    zone = Zone(name="test", width=20, height=20)
+    mob = spawn_mob(template, x=0, y=0, zone=zone)
+
+    assert mob.schedule is not None
+    assert len(mob.schedule.entries) == 1
+    assert mob.schedule.entries[0].hour == 8
+    assert mob.schedule.entries[0].state == "patrol"
+
+
+def test_get_game_hour_convenience_function():
+    """get_game_hour() returns current game hour from global instance."""
+    from mudlib.gametime import init_game_time
+
+    # Initialize game time for this test
+    init_game_time()
+    hour = get_game_hour()
+    assert 0 <= hour < 24
+
+
+def test_process_schedules_skips_converse_state():
+    """process_schedules skips mobs in converse state to preserve conversation."""
+    zone = Zone(name="test", width=20, height=20)
+    mob = Mob(
+        name="conversing_npc",
+        location=zone,
+        x=5,
+        y=5,
+        behavior_state="converse",
+    )
+    entries = [
+        ScheduleEntry(hour=6, state="working", location={"x": 10, "y": 10}),
+    ]
+    mob.schedule = NpcSchedule(entries=entries)
+    mobs.append(mob)
+
+    # Process at hour 6 (schedule would normally transition to working)
+    process_schedules(mobs, 6)
+
+    # Mob should still be in converse state, not moved
+    assert mob.behavior_state == "converse"
+    assert mob.x == 5
+    assert mob.y == 5
+    # schedule_last_hour should not be set (processing was skipped)
+    assert mob.schedule_last_hour is None
diff --git a/tests/test_server.py b/tests/test_server.py
index 47a8b23..08a071b 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -175,6 +175,8 @@ async def test_game_loop_calls_clear_expired():
         patch("mudlib.server.process_mobs", new_callable=AsyncMock),
         patch("mudlib.server.process_resting", new_callable=AsyncMock),
         patch("mudlib.server.process_unconscious", new_callable=AsyncMock),
+        patch("mudlib.server.get_game_hour", return_value=12),
+        patch("mudlib.server.process_schedules"),
     ):
         task = asyncio.create_task(server.game_loop())
         await asyncio.sleep(0.25)