We also have similar issues where users request different duration for disappearing messages:
I tried to collect some stackexchange questions about duration input:
- touch screen - Time (duration) entry in webapp - pros/cons of various designs - User Experience Stack Exchange
- forms - Standard to let user select duration for hours and minutes - User Experience Stack Exchange
- forms - What is the best input control for setting the duration of time spanning minutes and hours? - User Experience Stack Exchange
- Element to input Duration - User Experience Stack Exchange
Seems every messenger has a bit different options and a bit different input every time.