Mi first official edit with an account was made in Mar 27, 2006 1:00 PM, thou I was already reading Wikipedia and possibly editing as an IP some time before that.

This user is a member of WikiProject Fraternities and Sororities.	This user is proud to have been a Wikipedian since Mar 27, 2006.	This user participates in WikiProject Puerto Rico.
en-5 This user can contribute with a professional level of English.	This user has been editing Wikipedia for more than 15 years—since March 27, 2006.	es Este usuario tiene el español como lengua materna.
This user has pending changes reviewer rights on the English Wikipedia. (verify)	This user has rollback rights on the English Wikipedia. (verify)	This user has autopatrolled rights on the English Wikipedia. (verify)

https://en.wikipedia.org/wiki/Wikipedia:Citation_templates