Duration questions show up constantly and still get fumbled. Payroll wants hours between punch-in and punch-out. A student wants to know how long the lab block actually ran. Someone asks how much time sits between 9:15 and 5:45 and three people do mental math differently. The form above is the boring fix: start time, end time, read the gap—plus a next-day switch when the shift crosses midnight.
Same calendar day is the default. If the end clock is earlier than the start, the page assumes you forgot the overnight box, not that you traveled backward in time. Night work is the usual place that happens—10:00 PM to 6:30 AM with end on the next day is the shape worth running once before you paste hours into a timesheet.
The default pair on the form—9:15 AM through 5:45 PM—is an eight-and-a-half-hour day people still verify after estimating. Breaks are not subtracted here; if lunch is unpaid, take it off on your side before you copy the total.
Measure a span vs add to a clock
This page answers how long between two times. It does not push a duration forward from a start clock—that is the add-time habit. When the question is "what time is it 2 hours 45 minutes after 9:30," add 2 hours 45 minutes to 9:30 AM on the add page instead of faking an end time here.
Calendar dates are a different tool entirely. If the gap crosses days on the calendar—not just past midnight on one work night—use the date difference pages, not a longer overnight checkbox.
Before you copy the hours line
Read the detail under the result—it shows decimal hours as well as h/m/s. Plenty of people round the wrong direction for billing. Copy start, end, and whether next-day was checked so the thread does not relitigate it Thursday.
- Next-day box only for end time on the following morning.
- Unpaid breaks: subtract manually before you trust the total.
- AM/PM typos in notes do not match 24-hour fields—fix the inputs.
Shift planning and stacked blocks are where small mistakes compound; the shift time addition note walks through reading totals aloud without turning this into a manual.
Ordinary scheduling math, not legal or payroll advice. When the hours matter, keep both clock values with the duration you paste.