Too restrictive assumptions about calendar weeks

[HeikoTheissen]

odata-vocabularies/vocabularies/Common.xml

Lines 821 to 822 in 79c5025

	<String>Property encodes a calendar week number as string following the logical pattern WW consisting of two digits.
	The string matches the regex pattern 0[1-9]|[1-4][0-9]|5[0-3]

makes too restrictive assumptions about what a week is. As explained on Wikipedia, if a leap year in the US starts on Saturday and ends on Sunday, that year has 54 weeks (the first and last of which contain only one day each), but the pattern above does not allow week numbers beyond 53.

Attempts at a calendar-week-based arithmetic should perhaps be discouraged.