Automatic calendar alarms for iPhone
Never be late again.
Connect Google Calendar, Apple Calendar, or Outlook Calendar once. OnTimer automatically turns upcoming events into alarms that stay visible until you respond, without rebuilding your schedule.
Team Standup
Tomorrow • 9:00 AM
OnTimer
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Team Standup
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OnTimer
now
Team Standup
Starts in 2m - Tap to Dismiss
OnTimer
now
Team Standup
Starts in 2m - Tap to Dismiss
The Last 5 Minutes
You did not forget. The reminder disappeared.
Most people are not late because they never knew what was coming. They saw the reminder, planned to move in a minute, got pulled back into something, and missed the final window.
Calendar notifications inform you.
They appear with every other alert, then leave you alone to remember what to do next.
OnTimer alarms make you act.
They stay visible until you respond, so the moment to move is harder to miss.
Automatic by design
This is not another place to manage reminders.
OnTimer works from your existing calendars and creates alarms automatically, so staying on time does not become another system to manage.
No manual alarm setup for every meeting
Work and personal calendars in one place
Alarms stay aligned when your schedule changes
Read-only calendar access
Where it helps
Built for moments where being late has a cost.
Meetings are the everyday case, but the same alarm behavior helps whenever the calendar event matters.
How it works
Connect once. Stay on time automatically.
Your calendar remains the source of truth. OnTimer handles the timing layer before the moment to join, leave, or wrap up.
01
Connect your calendars
Use the calendars you already rely on: Google Calendar, Apple Calendar, and Outlook Calendar.
Google Calendar
Outlook Calendar02
OnTimer creates alarms
Upcoming events get alarms automatically, without rebuilding your schedule.
03
Move before it is too late
When it is time to join, leave, or wrap up, OnTimer keeps the alert in front of you.
Time To Leave / Planning tools
Plan ahead with free time calculators.
Work backward from flights, appointments, wake-up times, cruises, and travel so you know exactly when to leave.
FAQ
Frequently Asked Questions
Short answers for the questions people usually have before trying OnTimer.
What is OnTimer?
OnTimer is a calendar alarm app for iPhone. It connects to your Google Calendar, Apple Calendar, or Outlook Calendar and triggers loud, persistent alarms before meetings and events so you are less likely to miss them or arrive late.
What is a calendar alarm app?
A calendar alarm app connects to your existing calendar and fires persistent, interruptive alarms before each event, not passive notifications that disappear on their own.
Can you turn Google Calendar, Apple Calendar, or Microsoft Outlook Calendar events into alarms?
Not natively. Google Calendar, Apple Calendar, and Outlook Calendar send notifications. OnTimer connects to those calendars and turns events into persistent alarms on iPhone.
What is the difference between a calendar notification and a calendar alarm?
A notification informs you and can disappear whether or not you act on it. An alarm interrupts you and requires a response before it stops.
What is the Last 5 Minutes Problem?
The Last 5 Minutes Problem is the gap between knowing about a meeting and actually acting in time. Persistent alarms help close that gap by staying on screen until you respond.
How is OnTimer different from normal calendar notifications?
Normal calendar reminders are passive notifications that are easy to swipe away or ignore. OnTimer fires a louder, more persistent alarm that stays on screen until you actively dismiss it.
Can OnTimer remind me when it is time to leave?
Yes. For calendar events with a location, OnTimer offers Time To Leave alerts based on travel time and traffic. Time To Leave is a paid feature.
Does OnTimer work with multiple calendars?
Yes. OnTimer supports multiple calendars, including Google Calendar, Apple Calendar, and Outlook Calendar.
Who is OnTimer best for?
OnTimer is useful for busy professionals, people with back-to-back meetings, people who miss normal reminders, and people who struggle with time blindness or chronic lateness patterns.
Learn
Explore calendar alarm guides.
Deep dives on notification failure, calendar alarms, Time To Leave, and the moments where a passive reminder is not enough.
- Why Calendar Notifications Fail (And What Actually Works)
- The Last 5 Minutes Problem: Why Notifications Fail
- Why Notifications Fail (And Persistent Alarms Work Better)
- Calendar Notifications Not Working? Why Reminders Fail
- Turn Calendar Events Into Alarms
- Best Calendar Alarm App for iPhone Calendars
- Meeting Reminder App for iPhone
- Persistent Calendar Reminders
- Calendar Notifications vs Alarms
- Why Calendar Reminders Fail
- ADHD Time Blindness Tools
Medication timing
More scheduled moments.
OnTimer works from calendar events, including medication timing and other recurring schedules people cannot afford to miss.
Download OnTimer
Let your calendar keep you moving.
Download OnTimer for iPhone and turn your calendar into automatic alarms for the moments you need to act.
Android? Join the waitlist.