I am not certain that date-of-subscription is available for those who
subscribed under an older version such as 1.8c or earlier.   With 1.8d,
besides the use of "query" you can also do a

REView <listname> by date

However when this command is issued, subscription dates are not always
available for the earliest members. I am not certain if there is another
way to glean this information from the logs if they are stored.

Cheers,  Louise Parsons
co-listowner, Penstemon-L
mailto:[log in to unmask]
http://www.peak.org/~parsont/rockgard/