90 Minute Timer
Ninety minutes for block periods and long exams.
Activity
Time
Station rotations
4 × 1 hour 30 minutes, 60s to switch · 1 hour 30 minutes total
Press Show to class for the board or projector. The disc shrinks and turns yellow, then red. Space starts and pauses. The screen stays awake while the timer runs.
Time's up!
Great work, everyone.
What a 90 minute timer is good for in class
- Block scheduling: a full 90-minute class.
- Long exams and final exam sessions.
- Three 28-minute rotations with 2 minute switches (88 minutes).
Running one of these every day? See the test timer and station rotation timer for set-up tips.
How the 90 minute timer looks on the board
The disc starts full and shrinks clockwise. Its colour tells the class how much time is left, even from the back of the room:
| Disc | Clock shows | Meaning |
|---|---|---|
| Green | From 1:30:00 down to 45:00 | More than half the time left |
| Yellow | From 45:00 down to 18:00 | Less than half left |
| Red | The last 18 minutes | Final 20 percent |
Sounds
- A soft two-note warning chime at 1:00 left (you can turn it off).
- Three short blips at 0:03, 0:02 and 0:01.
- A rising end chime, “Time's up!” on the board and a burst of confetti (skipped if your device is set to reduce motion).
Splitting 1 hour 30 minutes into parts
For a long session, Station rotations can split the time into parts with a short break between them. Some ways to divide 1 hour 30 minutes of work, with 2 minute breaks added between parts:
| Parts | Each | Breaks | Total |
|---|---|---|---|
| 2 | 45 min | 2 min | 1:32:00 |
| 3 | 30 min | 4 min | 1:34:00 |
| 4 | 22 min | 6 min | 1:34:00 |
Questions teachers ask
How does the clock show 90 minutes?
It shows 1:30:00 (one hour, thirty minutes). The disc turns yellow at 45:00 left and red at 18:00 left.
How do I start a 90 minute timer?
This page is already set to 1:30:00. Press Start or the space bar. To put it on the board, press Show to class: the controls disappear and the timer fills the screen. Tap the screen to pause, press Esc to exit.
When does the 90 minute timer turn yellow and red?
It turns yellow with 45:00 left and red with 18:00 left. You can turn colour changes off so the disc stays green.
What sounds does the 90 minute timer make?
A warning chime at 1:00 left, then 3-2-1 blips and an end chime. Sound only starts after you press a button, and the speaker button mutes everything.