How it's calculated
result time = start time + 30 minutes (wraps at 24:00)
start time = entered clock time. Adds 30 minutes (and shows +60/+90/+120 and −30); the day rolls over when the total crosses midnight.
Common questions
What time is 30 minutes after 11:45 PM?
It rolls past midnight to 12:15 AM the next day, which the tool flags as a day change.
Does it work in 24-hour time?
Yes, you can read the results in both 12-hour and 24-hour formats.