/
([ :]) # look for : and space as possible leading characters
([\"]?) # if there's a quote, disregard it
([0-9]{4}) # find the year
- # find the 1st dash
( # Group (4)
(
((0[13578] | (10|12)) # look for 31 day months
- # followed by the 2nd dash
(0[1-9]|[1-2][0-9]|3[0-1]) # and accept days up to 31
)
|