As ezPublish stored date and datetime values using Unix timestamps, the user cannot enter a date before 1.1.1970.
This is annoying, when you build a list of users with birth dates: "Young" persons can be stored, while persons of 35 years or older cannot have their birthday stored.
Suggestion: Either provide a new datatype, which allows this or enhance the current datatype to support some kind of offset (possibly defined per attribute).
So, if i define an offset of 70 years, the value "0" would define 1.1.1900, instead of 1.1.1970.
I don't know the range of the unix timestamp values though, but it should at least be possible to store dates for a century or two.