Connect the calendars you already use
Bring Apple Calendar, Google Calendar, and Outlook Calendar together, including work and school accounts.
Automatic calendar alarms
Never be late again.
OnTimer turns your calendar into automatic alarms that stay in front of you until you respond—so you know when to join, leave, or act.
Available now for iPhone. Android users can join the waitlist.
“Are you joining?”
The problem is not your calendar
You knew about the meeting. The reminder disappeared.
Schedules change. Traffic builds. A notification appears while you are doing something else. OnTimer closes the gap between knowing what is next and acting on time.
How OnTimer works
Your calendar becomes your alarm system.
Connect once. OnTimer automatically keeps your alarms aligned with your day.
Turn important events into alarms
OnTimer creates alarms automatically from your upcoming events. Each alarm stays on screen until you dismiss it, and Early Warning gives you time to wrap up before the main alarm.
Know when it is really time to leave
Time To Leave adjusts for traffic and how you travel.
Time To Fly finds flights in your calendar and works backward from your trip to the airport and airline-recommended arrival time. No extra flight entry required.
Automatic does not mean rigid
Your schedule. Your rules.
Home-screen event cards let you turn each alarm on or off, choose its sound, set an Early Warning, or open the original calendar event. Prefer alarms off by default? Turn off both automatic-alarm options in Recurring Meeting Manager, then tap the green bell only on events you want armed.
Download
Need an answer right now?
Start with the moment you are planning.
Use a free planning tool now. When the moment matters every day, let OnTimer keep watch automatically.
The useful details
A few things worth knowing.
OnTimer works with your calendar. It does not ask you to replace it.
What does OnTimer do?
OnTimer turns events from the calendars you already use into automatic alarms on iPhone. Alarms stay on screen until you dismiss them, so they demand an active response instead of disappearing like a passive calendar notification.
How is an OnTimer alarm different from a calendar notification?
A calendar notification can appear once and disappear. An OnTimer alarm stays in front of you until you dismiss it and can use the sound you choose.
Which calendars work with OnTimer?
OnTimer works with Apple Calendar, Google Calendar, and Outlook Calendar, including work and school accounts. OnTimer Pro supports multiple connected accounts.
Can I choose which events get alarms?
To start with alarms off, open Recurring Meeting Manager in Settings and turn off both automatic-alarm options. Then tap the green bell on any event card you want to arm.
Can I choose different alarm sounds?
Yes, you can customize alarms. Choose an alarm sound and assign a different sound to a specific event when it needs a distinct signal.
What is Early Warning?
Early Warning provides a lighter heads-up before the main alarm, with a default time that can be adjusted for a specific event.
What are Time To Leave and Time To Fly?
For calendar events with a usable location, Time To Leave can use travel time and traffic to alert you when it is time to head out. Time To Fly automatically discovers flights in your calendar and sets a leave-time alarm using the trip to the airport and the airline-recommended airport arrival time.
Can OnTimer ring through Silent mode or Focus?
On iOS 26.1 and later, High Alert can ring through Silent mode and Focus or Do Not Disturb when it is enabled and iOS permissions allow it. Without High Alert, sound and delivery still depend on the iPhone's notification, sound, and Focus settings.
Is OnTimer free?
OnTimer is free and includes automatic alarms for one calendar provider. Time To Fly can set an initial airport departure estimate on the free plan; OnTimer Pro can update it for traffic when background conditions allow. Pro also adds multiple calendar providers, Time To Leave, Early Warning, and additional controls.
Is OnTimer available for Android?
OnTimer is currently available for iPhone. Android users can join the waitlist and be notified when an Android version is ready. Join the Android waitlist.
One less thing to remember
Relax. You are on time.
Turn the calendar you already trust into alarms that keep you on time.