There are 2 fully programmable timers (Timer1 and Timer2), that can count either up or down. If the value is set to 00:00 they will count up from 0.  If set to a time, they count down from the preset value.

The trigger is set using the field next to the timer value:

ABS counts up or down continuously while the Tx is powered on and that model is selected.
THs runs whenever the throttle stick isn’t at idle 
THt starts the timer the first time throttle is advanced 
TH% counts up as a percentage of the full stick range.

Persistent, if ticked, means the value is stored in memory when the radio is powered off or model is changed, and will be reloaded next time the model is used.  When ‘Persistent’ is checked, the displayed time will show a super-script ‘P’ next to the time.

Minute call will beep / say the time every full minute, while countdown will also give announcements several more times during the last minute.

Note:  The Timer will show a negative sign when the time has counted down to zero and continued to count, and the display will flash.