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ISO week lookup
Time and date
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About this tool
Convert a calendar date to its ISO week-year, week number, weekday, and Monday-to-Sunday range.
Common uses
- Convert a calendar date to its ISO week-year, week number, weekday, and Monday-to-Sunday range.
- Choose the calendar date to convert.
How to use it
- 1.Choose the calendar date to convert.
- 2.Read YYYY-Www-d and the week’s Monday and Sunday dates.
Limits and notes
- ISO weeks begin on Monday and week 1 contains January 4; the ISO week-year can differ from the calendar year near New Year.
Frequently asked questions
What does this tool do?
Convert a calendar date to its ISO week-year, week number, weekday, and Monday-to-Sunday range.
What should I check before using the result?
ISO weeks begin on Monday and week 1 contains January 4; the ISO week-year can differ from the calendar year near New Year.