diff --git a/README.md b/README.md
index 38afa82..de517d7 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@
 
 ⚡️ Delivers core agent functionality in just **~4,000** lines of code — **99% smaller** than Clawdbot's 430k+ lines.
 
-📏 Real-time line count: **3,668 lines** (run `bash core_agent_lines.sh` to verify anytime)
+📏 Real-time line count: **3,689 lines** (run `bash core_agent_lines.sh` to verify anytime)
 
 ## 📢 News
 
diff --git a/nanobot/agent/tools/cron.py b/nanobot/agent/tools/cron.py
index 9f1ecdb..b10e34b 100644
--- a/nanobot/agent/tools/cron.py
+++ b/nanobot/agent/tools/cron.py
@@ -50,6 +50,10 @@ class CronTool(Tool):
                     "type": "string",
                     "description": "Cron expression like '0 9 * * *' (for scheduled tasks)"
                 },
+                "tz": {
+                    "type": "string",
+                    "description": "IANA timezone for cron expressions (e.g. 'America/Vancouver')"
+                },
                 "at": {
                     "type": "string",
                     "description": "ISO datetime for one-time execution (e.g. '2026-02-12T10:30:00')"
@@ -68,30 +72,46 @@ class CronTool(Tool):
         message: str = "",
         every_seconds: int | None = None,
         cron_expr: str | None = None,
+        tz: str | None = None,
         at: str | None = None,
         job_id: str | None = None,
         **kwargs: Any
     ) -> str:
         if action == "add":
-            return self._add_job(message, every_seconds, cron_expr, at)
+            return self._add_job(message, every_seconds, cron_expr, tz, at)
         elif action == "list":
             return self._list_jobs()
         elif action == "remove":
             return self._remove_job(job_id)
         return f"Unknown action: {action}"
     
-    def _add_job(self, message: str, every_seconds: int | None, cron_expr: str | None, at: str | None) -> str:
+    def _add_job(
+        self,
+        message: str,
+        every_seconds: int | None,
+        cron_expr: str | None,
+        tz: str | None,
+        at: str | None,
+    ) -> str:
         if not message:
             return "Error: message is required for add"
         if not self._channel or not self._chat_id:
             return "Error: no session context (channel/chat_id)"
+        if tz and not cron_expr:
+            return "Error: tz can only be used with cron_expr"
+        if tz:
+            from zoneinfo import ZoneInfo
+            try:
+                ZoneInfo(tz)
+            except (KeyError, Exception):
+                return f"Error: unknown timezone '{tz}'"
         
         # Build schedule
         delete_after = False
         if every_seconds:
             schedule = CronSchedule(kind="every", every_ms=every_seconds * 1000)
         elif cron_expr:
-            schedule = CronSchedule(kind="cron", expr=cron_expr)
+            schedule = CronSchedule(kind="cron", expr=cron_expr, tz=tz)
         elif at:
             from datetime import datetime
             dt = datetime.fromisoformat(at)
diff --git a/nanobot/cli/commands.py b/nanobot/cli/commands.py
index 235bfdc..3798813 100644
--- a/nanobot/cli/commands.py
+++ b/nanobot/cli/commands.py
@@ -720,20 +720,26 @@ def cron_list(
     table.add_column("Next Run")
     
     import time
+    from datetime import datetime as _dt
+    from zoneinfo import ZoneInfo
     for job in jobs:
         # Format schedule
         if job.schedule.kind == "every":
             sched = f"every {(job.schedule.every_ms or 0) // 1000}s"
         elif job.schedule.kind == "cron":
-            sched = job.schedule.expr or ""
+            sched = f"{job.schedule.expr or ''} ({job.schedule.tz})" if job.schedule.tz else (job.schedule.expr or "")
         else:
             sched = "one-time"
         
         # Format next run
         next_run = ""
         if job.state.next_run_at_ms:
-            next_time = time.strftime("%Y-%m-%d %H:%M", time.localtime(job.state.next_run_at_ms / 1000))
-            next_run = next_time
+            ts = job.state.next_run_at_ms / 1000
+            try:
+                tz = ZoneInfo(job.schedule.tz) if job.schedule.tz else None
+                next_run = _dt.fromtimestamp(ts, tz).strftime("%Y-%m-%d %H:%M")
+            except Exception:
+                next_run = time.strftime("%Y-%m-%d %H:%M", time.localtime(ts))
         
         status = "[green]enabled[/green]" if job.enabled else "[dim]disabled[/dim]"
         
@@ -748,6 +754,7 @@ def cron_add(
     message: str = typer.Option(..., "--message", "-m", help="Message for agent"),
     every: int = typer.Option(None, "--every", "-e", help="Run every N seconds"),
     cron_expr: str = typer.Option(None, "--cron", "-c", help="Cron expression (e.g. '0 9 * * *')"),
+    tz: str | None = typer.Option(None, "--tz", help="IANA timezone for cron (e.g. 'America/Vancouver')"),
     at: str = typer.Option(None, "--at", help="Run once at time (ISO format)"),
     deliver: bool = typer.Option(False, "--deliver", "-d", help="Deliver response to channel"),
     to: str = typer.Option(None, "--to", help="Recipient for delivery"),
@@ -758,11 +765,15 @@ def cron_add(
     from nanobot.cron.service import CronService
     from nanobot.cron.types import CronSchedule
     
+    if tz and not cron_expr:
+        console.print("[red]Error: --tz can only be used with --cron[/red]")
+        raise typer.Exit(1)
+
     # Determine schedule type
     if every:
         schedule = CronSchedule(kind="every", every_ms=every * 1000)
     elif cron_expr:
-        schedule = CronSchedule(kind="cron", expr=cron_expr)
+        schedule = CronSchedule(kind="cron", expr=cron_expr, tz=tz)
     elif at:
         import datetime
         dt = datetime.datetime.fromisoformat(at)
diff --git a/nanobot/cron/service.py b/nanobot/cron/service.py
index 4da845a..14666e8 100644
--- a/nanobot/cron/service.py
+++ b/nanobot/cron/service.py
@@ -32,7 +32,8 @@ def _compute_next_run(schedule: CronSchedule, now_ms: int) -> int | None:
         try:
             from croniter import croniter
             from zoneinfo import ZoneInfo
-            base_time = time.time()
+            # Use caller-provided reference time for deterministic scheduling
+            base_time = now_ms / 1000
             tz = ZoneInfo(schedule.tz) if schedule.tz else datetime.now().astimezone().tzinfo
             base_dt = datetime.fromtimestamp(base_time, tz=tz)
             cron = croniter(schedule.expr, base_dt)
diff --git a/nanobot/skills/cron/SKILL.md b/nanobot/skills/cron/SKILL.md
index 7db25d8..cc3516e 100644
--- a/nanobot/skills/cron/SKILL.md
+++ b/nanobot/skills/cron/SKILL.md
@@ -30,6 +30,11 @@ One-time scheduled task (compute ISO datetime from current time):
 cron(action="add", message="Remind me about the meeting", at="<ISO datetime>")
 ```
 
+Timezone-aware cron:
+```
+cron(action="add", message="Morning standup", cron_expr="0 9 * * 1-5", tz="America/Vancouver")
+```
+
 List/remove:
 ```
 cron(action="list")
@@ -44,4 +49,9 @@ cron(action="remove", job_id="abc123")
 | every hour | every_seconds: 3600 |
 | every day at 8am | cron_expr: "0 8 * * *" |
 | weekdays at 5pm | cron_expr: "0 17 * * 1-5" |
+| 9am Vancouver time daily | cron_expr: "0 9 * * *", tz: "America/Vancouver" |
 | at a specific time | at: ISO datetime string (compute from current time) |
+
+## Timezone
+
+Use `tz` with `cron_expr` to schedule in a specific IANA timezone. Without `tz`, the server's local timezone is used.