What does Simple Week Number do that other Date & time pages on this site do not?

Week index from Jan 1 (not ISO); also returns year and day of year. Short version: Simple week number with year and day-of-year.

Does Simple Week Number upload my file or text to Tool-You servers?

No. Simple Week Number runs in this browser tab. Files stay on the device. Limit note: Not ISO week numbering.

Should I use ISO Week Number instead of Simple Week Number?

Use Simple Week Number when you need Simple week number with year and day-of-year. Use ISO Week Number when you need ISO-8601 week and ISO year. They share a category (Date & time) but not the same job.

What are the limits of Simple Week Number?

Not ISO week numbering. Also: Week index from Jan 1 (not ISO); also returns year and day of year.

Simple Week Number

Simple week number with year and day-of-year.

Week index from Jan 1 (not ISO); also returns year and day of year.

What Simple Week Number does

Week index from Jan 1 (not ISO); also returns year and day of year.

The interactive controls for Simple Week Number load after this article so crawlers still read the instructions. Path /datetime/week-number-simple is the canonical address. Work happens on this device; Tool-You does not take a copy of the file or pasted text for Simple Week Number.

How to use Simple Week Number

Confirm you need Simple Week Number, not ISO Week Number (ISO-8601 week and ISO year.). Address: /datetime/week-number-simple.
Enter the numbers or dates Simple Week Number uses. Simple week number with year and day-of-year.
Read the result as Simple Week Number defines it — not as Week of Month (Week-of-month plus how many weeks the month has.). Week index from Jan 1 (not ISO); also returns year and day of year.
Simple Week Number is an estimate in the browser, not professional advice. Not ISO week numbering.
Need a different formula? Try Week of Month (Week-of-month plus how many weeks the month has.) instead of stretching Simple Week Number.

When not to use Simple Week Number

Skip Simple Week Number when a neighbor tool matches better — start with ISO Week Number or Week of Month — or when the description already warns the job will fail. In the tool’s own words: Week index from Jan 1 (not ISO); also returns year and day of year.

Questions about Simple Week Number

What does Simple Week Number do that other Date & time pages on this site do not?: Week index from Jan 1 (not ISO); also returns year and day of year. Short version: Simple week number with year and day-of-year.
Does Simple Week Number upload my file or text to Tool-You servers?: No. Simple Week Number runs in this browser tab. Files stay on the device. Limit note: Not ISO week numbering.
Should I use ISO Week Number instead of Simple Week Number?: Use Simple Week Number when you need Simple week number with year and day-of-year. Use ISO Week Number when you need ISO-8601 week and ISO year. They share a category (Date & time) but not the same job.
What are the limits of Simple Week Number?: Not ISO week numbering. Also: Week index from Jan 1 (not ISO); also returns year and day of year.