You agree that you may not transfer your domain name registration to another domain name registrar during the first sixty (60) days from the effective date of your initial domain name registration with xyzregister.com.

I got a domain name registered since Nov 2001 at registrar X. Last month i transfered it to registrar Y. It's been a month since then but now i must transfer it to another person, at registrar Z. Can i do this now? 30 days after the last transfer? Or i have to wait at least 60 days?

Wait 60 days.

you can transfer a domain if you renewed,transfered, register it in the past 60 days

Current ICANN rules prevents domain transfers if they have been
registered for less than 60 days or newly transferred to another
registrar and hasn't passed the 60-day mark with the new one.
Any additional restrictions depends on the registrar your domain
name is currently with.

Go Daddy takes it steps further by preventing transfers within
them or out of them if the name has been renewed recently until
after about 60 calendar days, down to the last second in their
systems.

Check with your registrar to be sure.

Simply push the domain to another account at the same registrar if there is such an option. Godaddy, Enom let you do it...