Fill in the table on the left with the start and end times of a task, and the task being completed. Then click submit, which will sum the hours and place them in the proceeding table.
You can enter times in any of these formats (where HH means Hours and MM means Minutes): HH:MM,HH.MM,HH,MM. Examples: 1:15, 12.35, 7,37.
You can also enter 3 or 4 digit numbers, and they'll be split up into the formats HMM and HHMM. Examples: 230 will become 2:30, and 1012 will become 10:12.