ASP.NET Gridview (setting date format)

A very quick way to set dateformat for grid view, is to go to

1. gridview task > edit column
2. select the field in 'selected fields' section >
   
3. under 'boundfield properties' locate: 'dataFormatString' and set it to '{0:dd/MM/yyyy}'

SO far it works for 1 gridview but didnt work for another.... hmm im puzzled.