The pebble time watchface dims pretty fast and it only lasts 3 seconds, unfortunately there is no option right to increase that. in watchface it is possible to change this behavior programatically here is how i did it.

1.   static int seconds;
2.   static void set_backlight(){
3.   light_enable_interaction();
4.   if (seconds<=4)return;
5.   app_timer_register(3000,set_backlight, NULL);
6.   }
7.   static void accel_tap_handler(AccelAxisType axis,int32_t direction) {
8.   light_enable_interaction();
9.   seconds = 10;
10.   app_timer_register(3000,set_backlight, NULL);
11.   }
12.   static void main_window_load(Window *window) {
13.   ...
14.   accel_tap_service_subscribe(&accel_tap_handler);
15.   ...
16.   }
17.   static void tick_handler(struct tm *tick_time, TimeUnits units_changed) {
18.   if (seconds>0)seconds--;
19.   ...
20.   }
21.   static void init() {
22.   ...
23.   tick_timer_service_subscribe(SECOND_UNIT, tick_handler);
24.   ...
25.   }
26.