Time of Day

Some equipment and monsters change behavior depending on the Time of Day, and some quests can only be completed at certain hours in Vana'diel.

Game Term	Hours	Affects
Daytime	06:00-18:00	Arco De Velocidad, Brisingamen (HQ), Clown's Subligar (HQ), Dandy Spectacles (HQ), Daylight Dagger, Fenrir items, Garden Bangles (HQ), Horror Head II, Ladybug Ring (HQ), Ladybug Earring (HQ), Louhi's Mask, Lycopodium Sash, Nocturnal mobs go to sleep, Sunlight Pole, Vampire Cloak
Nighttime	18:00-06:00	Brisingamen (HQ), Clown's Subligar (HQ), Dandy Spectacles (HQ), Diurnal mobs go to sleep, Eerie Cloak +1, Fenrir items, Giant Bats spawn in outdoor areas, Horror Head, Louhi's Mask, Ninja Artifact Armor, Ninja Relic Armor, Nightmare Sword, Schwarz Axt, Shiranui, Vampire Boots, Vampire Cloak, Vampire Earring, Vampire Mask
Dusk to Dawn	17:00-07:00	Koga Hakama +1, Koga Hatsuburi +1, Koga Kyahan +1, Koga Tekko +1, Ninja Hakama +1, Ninja Kyahan +1, Rossignol
New Day	04:00	Magian Spectacles begin evaluating a new day
Dawn	06:00-07:00
Day	07:00-17:00
Dusk	16:00-18:00	Lovers in the Dusk
Evening	18:00-20:00
Dead of Night	20:00-04:00	Undead spawn in outdoor areas

In-game dawn and dusk are different from their real-life counterparts in that the in-game ones are considered part of daytime rather than nighttime.