Web alarm clock for 2:55 a.m.
While you watch the minutes and wait to open the chapel for night prayer, set the alarm for 2:55 am so the appointed moment does not slip past. The five minutes before 3:00 am are enough to check the key, switch on the entrance light, and stand ready without opening earlier than intended.
Because the chapel may be near humming electric fans, passing tricycles, or a noisy street, choose a signal you can clearly hear above that background. Raise the volume before settling down, then play a brief test and listen from the place where you will wait. Keep this page active and prevent your phone from going to sleep: if either happens, the alarm may stay silent and the chapel may remain locked when worshippers begin arriving.
As the household stays quiet around 2:55 am, place the phone close enough for a moderate signal to reach you instead of turning it up across the room. If others are sleeping, use vibration as extra notice on a firm surface, not as the only cue, and silence the sound as soon as you are awake. Prepare your keys and footwear beforehand so you can leave calmly without switching on unnecessary lights or disturbing anyone else in the house.