Use the date picker to choose the date you want to check. You can select any date from past, present, or future.
Click the "Query Week Number" button to calculate which week of the year your selected date falls into.
Browse the complete year calendar to see all weeks and their corresponding dates for better planning.
When you visit DayCheck.tools, you'll immediately see today's date and its corresponding week number displayed at the top of the page. This gives you instant access to the current week information without any additional steps.
When you query a date, the result will show:
DayCheck.tools uses the ISO 8601 international standard for week numbering. This ensures consistency and accuracy across different countries and systems.
If January 1st falls on a Friday, Saturday, or Sunday, it belongs to the last week of the previous year, not Week 1 of the new year.
December 29th, 30th, and 31st might belong to Week 1 of the following year if the week contains at least 4 days of the new year.
Using a standardized system means:
A: This happens when January 1st falls on a Friday, Saturday, or Sunday. According to ISO 8601, Week 1 must contain at least 4 days of the new year, so these dates belong to the last week of the previous year.
A: Yes! A year has 53 weeks when January 1st falls on a Thursday, or when it's a leap year and January 1st falls on a Wednesday. This happens approximately every 5-6 years.
A: The tool automatically detects and uses your local timezone for calculating "today's" information. When you query specific dates, the calculations are based on the date itself, regardless of timezone.
A: Yes, completely free! There are no restrictions, registrations, or premium features. We believe date utilities should be accessible to everyone.
A: Absolutely! The calculator works for any date from 1900 to 2100, making it perfect for historical research, project planning, and future scheduling.
Use the year navigation arrows (β β) in calendar view to quickly browse between consecutive years without returning to the main page.
You can use your keyboard arrow keys to navigate the date picker quickly. Tab through form elements for faster data entry.
On mobile devices, the date picker will show your device's native date selection interface for the best user experience.
You can bookmark specific year calendar pages (like daycheck.tools/year_calendar/2024) for quick access to frequently needed years.
If you have questions that aren't covered in this guide, or if you encounter any issues while using DayCheck.tools, we're here to help!