To avoid retroactive expiration, you should instruct users to change their passwords prior to setting a password lifetime. The default is for none of the flags to be set. A value of 0 returns all four flags to their defaults. Both upper and lower-case letters are acceptable in specifying values for the flags. The default is never.
Date format is the same as for a date alone.
Surround the entire instance with quotes because it contains a space. That is, if name of user is an individual, this value is the maximum lifetime of a ticket issued to the user. For up to 30 days after password expiration, the user can use his or her old password to change passwords. The range of valid values is 0 through 254. By default, a user's password will never expire.