Sharepoint xsl ddwrt FormatDateTime issue

Question

I use the ddwrt:FormatDateTime function to format the output like yyyyMMdd. inputs like 01/01/2010 work fine but when the day gets over the number 12 the output is an emtpy string.

ddwrt:FormatDate(string(@myDate), 1033, 'yyyyMMdd')

At first I thought it could be a language specific problem but even none of those combinations work:

13/01/2010
01/13/2010
13.01.2010

Answer 1

I googled and found out that sharepoint uses ISO8601 format of the date: yyyy-mm-ddThh:mm:ssZ"

Th same page and the Microsoft origin state that the third parameter of the function is long and not the formatting string.