Does Previous Weekday upload my file or text to Tool-You servers?

No. Previous Weekday runs in this browser tab. Files stay on the device. Limit note: ISO weekday 1–7. Include-today optional.

Should I use Next Weekday instead of Previous Weekday?

Use Previous Weekday when you need Previous ISO weekday; optional include today. Use Next Weekday when you need Next ISO weekday; optional include today. They share a category (Date & time) but not the same job.

Previous Weekday

Previous ISO weekday; optional include today.

Finds the previous date whose ISO weekday matches 1–7. Optional include-today keeps today when it already matches. Unlike Next Weekday this walks backward.

What Previous Weekday does

Finds the previous date whose ISO weekday matches 1–7. Optional include-today keeps today when it already matches. Unlike Next Weekday this walks backward.

Practical limit for Previous Weekday: ISO weekday 1–7. Include-today optional. That is why output can differ from heavy desktop Date & time software. Read the tool-specific note again: Finds the previous date whose ISO weekday matches 1–7. Optional include-today keeps today when it already matches. Unlike Next Weekday this walks backward.

How to use Previous Weekday

Confirm you need Previous Weekday, not Next Weekday (Next ISO weekday; optional include today.). Address: /datetime/previous-weekday.
Enter the numbers or dates Previous Weekday uses. Previous ISO weekday; optional include today.
Read the result as Previous Weekday defines it — not as Weekday Name (Weekday name, ISO 1–7, and Sunday-based 0–6.). Finds the previous date whose ISO weekday matches 1–7. Optional include-today keeps today when it already matches. Unlike Next Weekday this walks backward.
Previous Weekday is an estimate in the browser, not professional advice. ISO weekday 1–7. Include-today optional.
Need a different formula? Try Weekday Name (Weekday name, ISO 1–7, and Sunday-based 0–6.) instead of stretching Previous Weekday.

When not to use Previous Weekday

Skip Previous Weekday when a neighbor tool matches better — start with Next Weekday or Weekday Name — or when the description already warns the job will fail. In the tool’s own words: Finds the previous date whose ISO weekday matches 1–7. Optional include-today keeps today when it already matches. Unlike Next Weekday this walks backward.

Questions about Previous Weekday

What does Previous Weekday do that other Date & time pages on this site do not?: Finds the previous date whose ISO weekday matches 1–7. Optional include-today keeps today when it already matches. Unlike Next Weekday this walks backward. Short version: Previous ISO weekday; optional include today.
Does Previous Weekday upload my file or text to Tool-You servers?: No. Previous Weekday runs in this browser tab. Files stay on the device. Limit note: ISO weekday 1–7. Include-today optional.
Should I use Next Weekday instead of Previous Weekday?: Use Previous Weekday when you need Previous ISO weekday; optional include today. Use Next Weekday when you need Next ISO weekday; optional include today. They share a category (Date & time) but not the same job.
What are the limits of Previous Weekday?: ISO weekday 1–7. Include-today optional. Also: Finds the previous date whose ISO weekday matches 1–7. Optional include-today keeps today when it already matches. Unlike Next Weekday this walks backward.