How to calculate the week number

[RoslynThomas]

Of the 52 weeks in a year, I want to know the week number that a date falls in, e.g. date - 05/08/2013 falls in Week No. 32. What's the formula to get this answer?

 

[VoG]

Try

=WEEKNUM(A1)

 

[RoslynThomas]

I'm embarrased .... I've been stuck on this one for time immemorial with the same formula & now I've realised that it wasn't working for me coz the format of the cell was set to text. Thank you