Knows your rotation
A/B, odd/even, or any 2–8 day rotation — plus traditional weekly schedules. Set it once at the start of the year and it tracks every day for you, including the days you don't teach.
Built for K–12 teachersIs today an A-day?
Is today an A-day?
Your alarm already knows.
ScheduleLock is the alarm app for teachers on rotating block schedules. It tracks your school's rotation, fires alarms only on school days, and lets you override any day with one tap.
Next AlarmA-Day
6:50AM
First Bell
In 8 min
3.7M
U.S. public school teachers
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A/B+
Block, rotating & traditional schedules
Built for the way you teach
Three features no other alarm app gets right.
Any alarm app can do "every Tuesday." None of them can do "every A-day," because an A-day isn't a weekday. ScheduleLock tracks the rotation itself — so your alarms follow your cycle, skip your breaks, and reset themselves every morning.
Off when you need off
Snow day? Late start? Half day? One tap silences a full day or shifts a single alarm. Resets itself by tomorrow — so you can't forget to flip it back.
Survives reboots and DND
Built on AlarmManager, not background timers. Bypasses Do Not Disturb. Lives through phone restarts. Fires when it's supposed to — every time.
How it works
Three steps, then it runs itself.
01
Configure
Tell it your rotation
Pick A/B block or traditional. Set your start date and term dates. Three fields, under a minute. ScheduleLock figures out the rest of the year.
02
Build
Build your alarm groups
Create A-day alarms, B-day alarms, every-day alarms. Custom times, custom labels, weekly cadence options when you need them.
03
Override
Override when life happens
One tap for a full day off. Individual alarm toggles for late-start days. Auto-resets tomorrow — no remembering to undo anything.
Why not a regular alarm app
Generic alarms don't know it's a B-day.
They handle "every Tuesday" fine. They have no concept of a cycle that drifts across the week, pauses for a break, and picks up where it left off.
Feature
ScheduleLock
Generic alarm app
Tracks A/B & multi-day rotations
✓
—
Honors term dates & school breaks
✓
—
Clears a whole day in one tap
✓
—
Overrides undo themselves by morning
✓
Sometimes
Share a whole schedule with a colleague
✓
—
Works offline, no account
✓
✓
Fires reliably after reboot
✓
Sometimes
Ready when you are
Stop second-guessing your alarm at 10pm on Sunday.
ScheduleLock is out now on the App Store and Google Play. Free, no account, 100% offline.