lua has os.time() and os.date() functions built-in so you can get the date or play around with it. You probably use os.time() first then add etc and then convert it to a normal string with os.date()
print ( os.date("%c").."\n"..os.date("%c",os.time()+60))
Fri Jan 28 16:20:59 2011
Fri Jan 28 16:21:59 2011