There are several intervals in Empires VIP PASS is based on 24 hours while Daily Summons is based on 23 hours.
Notes
New Daily Summons
23 hours
New Mystic Vision
16 hours edit ( now 8 hours )
New Titan
22 hours to hit
23 hours between spawns
VIP Pass
24 ( spawn)- 48 hours ( uncollected despawn )