Date & time Difference

Weeks between dates

From

Counting

Weeks —

The same gap in other units

Days —

Whole weeks —

Months —

Years —

Years, months, days —

Hours —

Minutes —

Note Enter both dates

Whole weeks plus the remainder

Weeks are days divided by seven. Ninety days is 12.857 weeks, or twelve whole weeks and six days. Both forms are shown, because a decimal week is rarely what anyone actually wants to act on.

How to count weeks between dates

1 Enter both dates.

2 Read the decimal week count and the whole-weeks breakdown.

3 Use whole weeks plus remainder for anything you have to schedule.

4 Switch to inclusive counting if both end days count.

Pregnancy is where week counting matters most and where the convention is least obvious: gestational age is counted in completed weeks plus days, written as "24w 3d", from the last menstrual period rather than from conception. Project planning uses the opposite convention, rounding partial weeks up because a sprint is a sprint. Neither is wrong; they are counting different things.

Questions

How many weeks between two dates? −

Divide the days by seven. Ninety days is 12 weeks and 6 days.

How many weeks in a year? +

Why does my pregnancy app differ? +

Should I round partial weeks up? +

How many weeks is 100 days? +

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