For teachers who run their room by the clock

The classroom timer that doesn’t drift — even when your laptop sleeps.

Set it to end at 9:02, and it ends at 9:02. LessonTimer stores your class times as clock times, not a stopwatch — so closing the lid between periods never costs you ten minutes you didn’t notice.

Start your free trial  → Free 14-day trial · Linux & Windows · macOS coming
Questions? Email [email protected] or get in touch
—:—— —M Next: nothing else scheduled
P1 — Class time
—:——
 
Live demo · counting down to the next real clock minute, right now, in your own timezone
The bug that started this

Most timers count seconds. Yours needs to count minutes on a clock.

A stopwatch-style timer

  1. 8:18 44‑minute timer starts for class
  2. 8:40 Laptop lid closes between tasks
  3. 8:50 Lid reopens — the OS suspended the clock the timer was counting from
  4. 9:12 Timer finally ends — ten minutes into the next thing you had planned

LessonTimer

  1. 8:18 Entry set to end at 9:02 — a clock time, not a duration
  2. 8:40 Laptop lid closes
  3. 8:50 Lid reopens — LessonTimer recalculates from the wall clock, not from where it left off
  4. 9:02 Ends exactly on time, as if it never slept
The actual app

Not a mockup — this is what's running right now

LessonTimer main window showing a running countdown, quick timers, and a class schedule table
Main window. A running timer, saved quick timers below it, and the day's schedule — each row a real class period with a start time, length and end time worked out for you.
LessonTimer schedule entry editor showing sound, repeat, volume and cue point settings
Editing a period. Pick the sound, how many times it repeats, how loud it is — live preview before you save.
What's actually in it

Built around how a teaching day really runs

01

Day profiles

Monday's schedule isn't Wednesday's. Save as many day profiles as your week needs and switch with one click.

02

Cue points inside one timer

A 50‑minute block with a warning at 4 minutes and another at 47 — one timer, several alerts, no extra setup.

03

Sound that cuts through the room

Five distinct cues plus your own recording, each with its own repeat count and volume — so “class starts” never sounds like “pack up.”

04

Readable from the back row

Fullscreen projection mode holds digit height to a quarter of the screen, with the terminal moment flashed, not just chimed.

Built for a choir teacher who needed to stop class at a clock time three minutes before the bell — reliably, in a room too loud to notice a timer that had quietly drifted.

Tested with real music teachers before release
Cost

One price, no subscription.

Every download starts with a free 14-day trial. After that, a license is a one-time purchase per teacher, not a subscription — buy it once, use it every year. Each seat can be moved to a new machine yourself at any time, no need to contact anyone. Prices in US dollars.

1 teacher $29
2 teachers $45
3 teachers $60
5 teachers $90
10 teachers $130
Whole school (up to 30 teachers) $299

Teaching on a schedule that can't slip?

Try it free for 14 days in your own classroom — no card needed. Then a one-time license keeps it running.

Start your free trial  → Questions? Email [email protected] or get in touch