Work out telling time practice instantly with clear inputs, formula shown and shareable results.
The start time is converted to minutes since midnight, the elapsed minutes are added, and the total is wrapped back into a 24 hour day before being split into hours and minutes. Working in minutes since midnight removes the base-60 stumbling block, which is why timetable questions become easy once a child adopts it.
Minutes since midnight
start = 60 x hour + minute
Finish time
finish = (start + minutes added) mod 1440, then hours = floor(finish / 60), minutes = finish mod 60
start = 60 x hour + minute. The start time is converted to minutes since midnight, the elapsed minutes are added, and the total is wrapped back into a 24 hour day before being split into hours and minutes.
Working in minutes since midnight removes the base-60 stumbling block, which is why timetable questions become easy once a child adopts it.
Enter start hour (24h), start minute, minutes to add. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.