A timer with aria-live changed to "polite".
The Illinois aria example of a timer and a 5-minute RSS feed update.
Another Illinois example which does wierd things. If the aria-live value is set to "polite", the numeric value of the timer is repeated many times in iOS. If the aria-live value is left as "assertive" JAWS announces "removed" sometimes. It is better to modify "Live Region 2: Log text" and set the live property value to "off" to allow the testing of just the timer.
Note that you may need to increase the speech rate of screen readers to have them announce the timer properly; otherwise the time changes faster than they can announce it, and the announced time becomes inaccurate.