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# Week Number

Kalipso - Form - Expressions - Functions - Functions Descriptions - Date Functions - Week Number

This Function returns a *\<numeric>*, which is the number of the week of the specified **Source** Date.

### Parameters

* **Source Date** *\<string> -* Date to get the week number from. This parameter must be in format YYYYMMDD.

{% hint style="info" %}
January first is always week 1. First day of week is Sunday.\
S M T W R F S\
1 2 3 <-- week #1\
4 5 6 7 8 9 10 <-- week #2
{% endhint %}