How long can a timer run?

[QDUNI]

Hi,

How long can a timer run without needing to reset the timer/device ?

Thnx in advance

[philj404]

The timer can run indefinitely without needing a reset. That said, if your code wants to schedule a task for over a month away, you may need to consider rollover issues.

(Internally the timer stores times as an unsigned long. The next time a task should run is also an unsigned long. The timer does not care what the particular value is, as it only compares the differences. When the difference between the current time and the time to run a task becomes positive, the task will run.)

You will need to consider unsigned long rollover issues if you want really long delays (waiting over 4294967295 ticks).
That's equivalent to:

• waiting over 49 days if using the default millis() times (four billion milliseconds)
• waiting over 1.19 hours if using micros() times

[QDUNI]

Thnx !