Find the week number of a date and its position within the year.
Counting weeks from 1 January gives a simple week number where week one starts on the first of the year. This differs from the ISO definition, which anchors weeks to Mondays. Two systems both called "week number" can differ by one, which is why reports comparing weekly data across tools need the definition checked.
Week Number
Week number = ⌈day of year ÷ 7⌉
Week number = ⌈day of year ÷ 7⌉ Counting weeks from 1 January gives a simple week number where week one starts on the first of the year. This differs from the ISO definition, which anchors weeks to Mondays.
Two systems both called "week number" can differ by one, which is why reports comparing weekly data across tools need the definition checked.
This calculator takes 3 inputs: Date year, Date month, Date day. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.