How calculations work

Date Sparrow treats a calendar date differently from an exact number of hours. Results show the choices that can change an answer.

Calendar dates

Date-only calculations use the familiar Gregorian calendar. Differences are shown in years, months, and days, with total days shown separately. When a target month has fewer days, the tool uses your choice to move to the last day or show an error.

End dates and workdays

You choose whether the ending date is counted. Workday calculations use your weekend, days off, and optional public holidays.

Time zones and clock changes

Time zone rules come from your browser. When clocks move forward or backward and a local time is missing or occurs twice, the tool uses the option you selected.

Repeating dates and calendar files

Repeating dates can be daily, weekly, monthly, or yearly and always have an end. Calendar files use the common .ics format. Before downloading a checked copy, the app lists anything it needs to remove or change.