WEEKNUM and ISOWEEKNUM functions. Get how many weeks in the year the date is.

Japanese version.

Get how many weeks in the year the date is.

How it works

ISOWEEKNUM

=ISOWEEKNUM(Date)
ArgumentOmissionSpecify
DateRequired argument.Target date.

It is a simple function to specify a date.

This is the format specified in ISO called the European week number system.
It has the following characteristics
Monday is treated as the beginning of the week.
The week with the first Thursday of the year is treated as the first week.

In this format, one week = 7 days is always maintained, even during the year-end and New Year holidays.

WEEKNUM

=WEEKNUM(Serial_number,Return_type)
ArgumentOmissionSpecify
Serial_numberRequired argument.Target date.
Return_type1Definition of week.

Return_type

The beginning of the week and the rules.

Return_typeBeginning of the week.First week of the year.
1SundayWeek including January 1.
2Monday"
11Monday"
12Tuesday"
13Wednesday"
14Thursday"
15Friday"
16Saturday"
17Sunday"
21MondaySame as ISOWEEKNUM.

The following are the same results.

  • Omission and 1 and 17.
  • 2 and 11.
  • 21 and ISOWEEKNUM.

All except 21 will be the first week of the year on January 1.

Example Results

Spill

If you specify the argument the cell range, it will be Spill.

Only ISOWEEKNUM supports Spill.

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Links

Date & Time(Microsoft Excel Functions)