Skip to content
Calciyums

Date Format Converter

Convert a date into other formats and see its weekday, day of the year and ISO week number.

Date & Time

Calculation

Calculated in your browser; what you enter is never sent to a server.

Result

Enter your values and calculate; the result will show up here.

How is it calculated?

Pick a date. The tool writes it in the Turkish (DD.MM.YYYY), US (MM/DD/YYYY) and international ISO 8601 formats, and shows the weekday, the day of the year, the ISO week, the quarter and the Unix timestamp.

Formula

ISO week: week 1 is the week containing the year's first Thursday; weeks start on Monday.

Example

Date: September 20, 2025 → Long format: September 20, 2025

Similar Tools

Toolbox Get your Toolbox ready.

Star the tools you use most and, with an account, they follow you to every device.

Create account

Frequently asked questions

What is an ISO week number?

Weeks start on Monday, and week 1 is the one containing the year's first Thursday. Early January can fall in week 52 or 53 of the previous year, and late December in week 1 of the next.

Which time does the Unix timestamp use?

Midnight (00:00) UTC on the chosen date.