Try the tool

Runs in this page. Your inputs are not uploaded or saved. Dates use your browser’s time zone.

Your result

Enter the recorded time and a later time. The result is elapsed days, hours, and minutes, without any claim about the item's present condition.

A worked example

From October 2 at 8:46 AM to October 2 at 9:41 AM is 55 minutes. From 11:30 PM to 12:15 AM the next day is 45 minutes.

Date and time both matter

The tool rejects invalid calendar dates and a later time before the recorded time. Daylight saving transitions use the browser's local time zone; ambiguous repeated times follow the browser's Date interpretation.

Keep the next check on your iPhone

Create the items manually in Is It Locked?. This browser draft does not transfer into the app. Check the items yourself, then record them.

Get the app free

iOS 27 or later. One place and one list are free.

The app records what you checked. It does not lock doors, switch off appliances, or verify their physical state.

Sources and review notes

Calculation conventions and boundary cases are documented above. The tool runs locally and is tested against arithmetic and calendar examples.