Add Weeks to a Date Calculator

Enter a start date and a number of weeks. Use a negative number to go back in time.

Updated October 27, 2026

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<iframe src="/embed/en/time-date/add-weeks-to-date-calculator/" width="480" height="640" title="Add Weeks to a Date Calculator" loading="lazy" style="border:0;max-width:100%"></iframe>
<script>window.addEventListener('message',function(event){if(event.origin!==''||!event.data||event.data.type!=='calc-embed-height')return;var f=document.getElementsByTagName('iframe');for(var i=0;i<f.length;i++){if(f[i].contentWindow===event.source){f[i].style.height=event.data.height+'px';}}});</script>

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Formula

new date = start date + (weeks × 7) days

The day of the week stays the same, because 7 days is one full week.

Worked example

31 January 2024 + 2 weeks: 2 × 7 = 14 days, and 31 January + 14 days = 14 February 2024, a Wednesday.

Frequently asked questions

How do I add weeks to a date?

Multiply the weeks by 7 and add that many days. Two weeks is 14 days, so 31 January 2024 plus 2 weeks is 14 February 2024.

Can I subtract weeks?

Yes, enter a negative number. 31 March 2024 minus 5 weeks is 35 days earlier, which is 25 February 2024.

Does the day of the week change?

No. Adding whole weeks always lands on the same weekday as the start date. 31 January 2024 and 14 February 2024 are both Wednesdays.

Are leap years handled?

Yes. Dates are counted on the real calendar, so 52 weeks (364 days) from 25 December 2023 is 23 December 2024, crossing 29 February 2024.

How we calculate

Add Weeks to a Date Calculator

Formula

Worked example

Frequently asked questions

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