diff --git a/TOOLS.md b/TOOLS.md
index 37a40d1..4a036dd 100644
--- a/TOOLS.md
+++ b/TOOLS.md
@@ -116,7 +116,8 @@ SKILL_DIR=~/.openclaw/workspace/skills/calendar
 $SKILL_DIR/scripts/calendar.sh send \
   --to "friend@example.com" \
   --subject "Lunch" --summary "Lunch at Tartine" \
-  --start "2026-03-20T12:00:00" --end "2026-03-20T13:00:00"
+  --start "2026-03-20T12:00:00" --end "2026-03-20T13:00:00" \
+  --alarm 1h  # 提前1小时提醒（默认1d，支持 1d/2h/30m）
 
 # 发送周期性邀请（--start 必须落在 BYDAY 指定的那天！）
 $SKILL_DIR/scripts/calendar.sh send \
diff --git a/skills/calendar/SKILL.md b/skills/calendar/SKILL.md
index 17b9683..559498e 100644
--- a/skills/calendar/SKILL.md
+++ b/skills/calendar/SKILL.md
@@ -63,7 +63,8 @@ $SKILL_DIR/scripts/calendar.sh send \
   --summary "Lunch at Tartine" \
   --start "2026-03-20T12:00:00" \
   --end "2026-03-20T13:00:00" \
-  --location "Tartine Bakery, SF"
+  --location "Tartine Bakery, SF" \
+  --alarm 1h
 ```
 
 ### Send Options
@@ -82,6 +83,7 @@ $SKILL_DIR/scripts/calendar.sh send \
 | `--organizer`   | No       | Organizer display name (defaults to `--from`)  |
 | `--rrule`       | No       | Recurrence rule (e.g. `FREQ=WEEKLY;COUNT=13;BYDAY=TU`) |
 | `--uid`         | No       | Custom event UID (auto-generated if omitted)   |
+| `--alarm`       | No       | Reminder trigger: `1d`, `2h`, `30m` (default: `1d`) |
 | `--account`     | No       | Himalaya account name (if not default)         |
 | `--dry-run`     | No       | Print ICS + MIME without sending                |
 
diff --git a/skills/calendar/TESTING.md b/skills/calendar/TESTING.md
index bb28836..a21af78 100644
--- a/skills/calendar/TESTING.md
+++ b/skills/calendar/TESTING.md
@@ -18,8 +18,10 @@ Generates the ICS and MIME email without sending. Check that:
 - MIME has `Content-Type: text/calendar; method=REQUEST`
 - Only `--to` recipients appear as attendees
 - Times and timezone look correct
+- ICS has `BEGIN:VALARM` with correct `TRIGGER` duration
 
 ```bash
+# Default alarm (1 day before)
 $SKILL_DIR/scripts/calendar.sh send \
   --to "mail@luyx.org" \
   --subject "Test Invite" \
@@ -27,6 +29,16 @@ $SKILL_DIR/scripts/calendar.sh send \
   --start "${TEST_DATE}T15:00:00" \
   --end "${TEST_DATE}T16:00:00" \
   --dry-run
+
+# Custom alarm (1 hour before)
+$SKILL_DIR/scripts/calendar.sh send \
+  --to "mail@luyx.org" \
+  --subject "Test Invite (1h alarm)" \
+  --summary "Test Event (1h alarm)" \
+  --start "${TEST_DATE}T15:00:00" \
+  --end "${TEST_DATE}T16:00:00" \
+  --alarm 1h \
+  --dry-run
 ```
 
 ## 2. Live Send: Self-Invite
diff --git a/skills/calendar/scripts/cal_tool.py b/skills/calendar/scripts/cal_tool.py
index 31cf8b1..6826e6b 100644
--- a/skills/calendar/scripts/cal_tool.py
+++ b/skills/calendar/scripts/cal_tool.py
@@ -210,11 +210,20 @@ def cmd_send(args):
         _validate_rrule_dtstart(rrule, start)
         event.add("rrule", rrule)
 
-    # 1-day reminder
+    # Reminder alarm
+    alarm_trigger = timedelta(days=-1)  # default
+    if args.alarm:
+        alarm_str = args.alarm
+        if alarm_str.endswith("d"):
+            alarm_trigger = timedelta(days=-int(alarm_str[:-1]))
+        elif alarm_str.endswith("h"):
+            alarm_trigger = timedelta(hours=-int(alarm_str[:-1]))
+        elif alarm_str.endswith("m"):
+            alarm_trigger = timedelta(minutes=-int(alarm_str[:-1]))
     alarm = Alarm()
     alarm.add("action", "DISPLAY")
     alarm.add("description", f"Reminder: {args.summary}")
-    alarm.add("trigger", timedelta(days=-1))
+    alarm.add("trigger", alarm_trigger)
     event.add_component(alarm)
 
     cal.add_component(event)
@@ -861,6 +870,7 @@ def main():
     send_p.add_argument("--rrule", default="", help="RRULE string (e.g. FREQ=WEEKLY;COUNT=13;BYDAY=TU)")
     send_p.add_argument("--uid", default="", help="Custom event UID")
     send_p.add_argument("--account", default="", help="Himalaya account")
+    send_p.add_argument("--alarm", default="1d", help="Reminder trigger (e.g. 1d, 2h, 30m)")
     send_p.add_argument("--dry-run", action="store_true", help="Preview without sending")
 
     # --- reply ---