Perfect! Thank you Ezrul. I had a look at #_users table and noticed I can change this in the 'registerDate' column for that user. Thats pretty easy.
I just want to confirm 1 more thing: is changing the registration date in this #_users table alone is good enough? Meaning, when I change the rego date here, do I also need to change that details anywhere for EasySocial or does EasySocial automatically respect the change once registration date is edited in Joomla's user table?