Weeks from today
How it works: Pick a calculator tab to either add or subtract weeks from a date, measure the gap between two dates, or map the weeks inside any month. Adjust week start, decimal precision, and ISO week settings to see results update instantly. Everything runs locally in your browser so no dates ever leave your device.
Overview
Use the Weeks from today calculator to add or subtract weeks from any starting date, compare the exact number of weeks between two dates, and explore how full and partial weeks stack up in any calendar month.
About
About Weeks from today
This tool combines three calculators in one: add or subtract whole and fractional weeks from a date, measure the time between two dates in weeks and days, and break down any month into full, partial, and ISO-numbered weeks. All math happens in your browser for instant, private results.
Features:
- Add or subtract decimal weeks from any start date
- Measure weeks between dates with remainder days
- List weekly ranges inside a chosen month
- Toggle Sunday or Monday week starts
- Optional ISO week number display
- Copy any result to your clipboard
FAQ
How many weeks are in a month?
Most months have between 4 and 5 weeks. A month with 28 days (like February in non-leap years) has exactly 4 weeks. Months with 30 or 31 days will typically have 4 full weeks plus 2-3 extra days, making up a partial 5th week. Some months can span 6 calendar weeks if they start near the end of a week.
Is a week always 7 days?
Yes, a week is always 7 days. Our calculator uses 7 days per week for all calculations. The days of the week are consistent worldwide (Monday-Sunday or Sunday-Saturday depending on your locale).
Why do some months show 6 calendar rows?
A month will show 6 calendar rows when the month starts near the end of the week and has 30-31 days. For example, if a 31-day month starts on a Saturday (or Sunday, depending on your week start setting), it will require 6 rows to display all days in the calendar view.
What's the difference between full and partial weeks?
A full week is a complete 7-day period that falls entirely within the month. A partial week occurs at the beginning or end of the month when there are fewer than 7 days remaining in that week. For example, if a month starts on a Wednesday, the first 5 days (Wed-Sun) would be a partial week.
Can I choose Sunday or Monday as the week start?
Yes! You can choose whether the week starts on Sunday or Monday in the tool's settings. This affects how weeks are calculated and displayed in the calendar view.
Does daylight saving time affect the calculations?
No, our calculator normalizes all dates to avoid DST issues. We use noon local time for all date calculations, which prevents any potential problems that might occur when clocks change for daylight saving time.
How accurate are the calculations for very large date ranges?
The calculations are accurate for any date in the Gregorian calendar (after 1582). However, for very large date ranges (hundreds or thousands of years), keep in mind that calendar systems and week numbering have changed historically in some regions.
What are ISO week numbers?
ISO week numbers are a standard way to count weeks in a year according to the ISO 8601 standard. Week 1 is the week containing the first Thursday of the year, and weeks start on Monday. This means some dates in late December or early January might belong to a week in the adjacent year.