Date and Time Duration Calculator

Measure a multi-day event in days, hours, and minutes, with an explicit time zone and DST handling.

Time-zone rules use your browser’s IANA data. Repeated local hours expose an earlier/later choice.

How to use date and time duration calculator

  1. Choose the start and end local date-times
  2. Choose the event time zone and repeated-hour occurrence
  3. Read the actual elapsed duration

Worked example

January 1, 2026 09:00 to January 3, 2026 12:30 in UTC

2 days 3 hours 30 minutes

How the result is calculated

Local date-times are resolved in the selected IANA zone, then UTC instants are subtracted. A skipped daylight-saving time is rejected and repeated times require an occurrence choice.

Inputs stay in your browser. You can use this tool without joining the waitlist or creating an account.

From a calculation to a daily glance

Keep the whole month in view.

Add the event to your calendar with its start and end dates. A monthly widget can show a continuous multi-day event bar.

  1. 1Add the events you want to see to your calendar.
  2. 2Enable that calendar in the app.
  3. 3Add Monthly Calendar; use Edit Widget → Design to choose its look.
Get early accessExplore widget designs

Web results do not automatically sync to the app. Setup is manual; calendar events appear through your enabled calendars.

February
SMTWTFS
1
2
3
4
5
6
7
Birthday ♡
8
9
10
11
12
13
14
MeetingsCelebration
15
16
17
18
19
20
21
CelebrationWorkshopMeetingProject reviewTeam dinner
22
23
24
25
26
27
28
Vacation
1
2
3
4
5
6
7
Monthly Calendar · example design from the app

Frequently asked questions

How does this date and time duration work?
Local date-times are resolved in the selected IANA zone, then UTC instants are subtracted. A skipped daylight-saving time is rejected and repeated times require an occurrence choice.
How can I use the result with Monthly Calendar Widgets?
Add the event to your calendar with its start and end dates. A monthly widget can show a continuous multi-day event bar.
Do I need an account to use this tool?
No. The tool works in your browser without an account. Your inputs are not sent to our servers. Downloaded files stay on your device.

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