When you haven’t access to SO and just have to alter database date…
# Fix Date:
ALTER SYSTEM SET fixed_date = '2016-04-05-12:00:00';
# Unfix Date:
ALTER SYSTEM SET fixed_date = NONE;
OBS: Just to make it clear: The date will be really “fixed”. The time will “stop”. Seconds, minutes will not advance…
Matheus.