Light of Dawn is a level 34 Holypaladin ability. The ability sends a cone of light in front of the paladin, healing up to 5 of the lowest health party/raid members in a 15 yard area in front of the caster.
Patch 7.0.3 (2016-07-19): Now affects 5 targets, down from 6, and cost mana instead of Holy Power. Healing increased by 140%.
Patch 6.0.2 (2014-10-14): Now has a 1.5-second cast time (up from instant cast).
Hotfix (2012-11-27): "Light of Dawn's healing has been increased by 5%."
Patch 4.3.0 (2011-11-29): Now affects 6 targets (base effect), up from 5.
Hotfix (2011-02-18): "Light of Dawn no longer heals targets outside the paladin's party or raid. It correctly heals up to 5 targets in the paladin's raid."
Hotfix (2011-02-14): "The hotfix to [Beacon of Light] and Light of Dawn on February 11 did not produce the intended results and has been reverted. Light of Dawn should still trigger Beacon of Light."
Hotfix (2010-12-21): "Light of Dawn is now properly locked out when the Holy spell tree is locked out and cannot be used for the duration of the lock."
Patch 4.0.3a (2010-11-23): Redesigned. It no longer has an enforced cooldown, now costs Holy Power instead of mana, and scales in direct proportion to the amount of Holy Power used. In addition, it now heals the 5 most injured group targets (including self) in a 30-yard frontal cone.