Substitution Timer
Keep game substitutions on time with a clear running clock, device alerts and a downloadable log.
Save and export
Plan builder
Set up your game, team or session in one place.
Game settings
Set your period length and substitution interval, then start the clock when play begins.
The timer uses the device clock. Keep this page open during the game; if the tab is backgrounded, it catches up from elapsed time.
GAME CLOCK
Substitution timer
Period 1 of 4
6:00
until next substitution alert
Start the timer to receive substitution alerts here.
Substitution log
Alerts are recorded automatically as the game clock reaches each interval.
No alerts yet. Your log will appear here as the timer runs.
Save and share capture a paused snapshot. Opening a snapshot never starts the timer.
For general information only, not professional advice. Check the official sources below. Use your own judgement and speak to a qualified professional before you act. This plan is a guide. Follow your league, school or association rules.
Last checked:
How to use it
- Set the length of each period, how often you want a substitution alert, and the number of periods.
- Start the timer when play begins. The display counts down to the next alert and shows the current period.
- Pause the clock during a stoppage, then resume it when play restarts. Reset to clear the elapsed time and start a new game.
- Download the substitution log as a CSV file when one or more alerts have occurred.
How it works
- The timer measures elapsed time against the device clock, so a delayed browser refresh catches up instead of losing elapsed time. Pausing stores the elapsed time and resuming continues from that point.
- An alert is recorded at each interval that falls within a period. An interval that does not divide the period evenly does not add a final partial interval. The alert list resets at the start of each period.
- The example uses four 12-minute periods with a 6-minute interval. It creates alerts at 6:00 and 12:00 in each period, for eight alerts total. The log stays in this page and is downloaded only when you choose.
Alerts across the game
- A
- total substitution alerts
- T
- minutes per period
- I
- minutes between alerts
- P
- number of periods
Worked example
The brackets mean round down. A 12-minute period gives two 6-minute alerts. Across four periods, that is eight alerts. An incomplete final interval does not add an alert.
Worked example
Set the game clock
4 periods × 12 minutes = 48 minutes
Set period length to 12 minutes, substitution interval to 6 minutes and periods to 4. Start the timer at kickoff.
Follow each substitution alert
2 alerts per period × 4 periods = 8 alerts
The clock alerts at 6:00 and 12:00 in period 1, then repeats at 6:00 and 12:00 in periods 2, 3 and 4. The log contains eight alerts.
Frequently asked questions
Does the timer keep running when I pause it?
No. Pause freezes elapsed time. Resume continues from the saved elapsed time.
Will the timer miss an alert if I switch tabs?
The timer compares against elapsed device time and catches up when the page runs again. Keep the page open and visible when possible so the alert is easy to notice.
Does the interval restart each period?
Yes. The substitution interval starts again at the beginning of every period.
What if the interval does not fit evenly into the period?
Only full intervals within the period create alerts. For a 10-minute period with a 6-minute interval, the alert is at 6:00; there is no additional alert at 10:00.
Where is the substitution log stored?
It stays in the open page until you reset or close it. Download a CSV to keep a copy.