0 ▁days ▁long . ▁ ▁Character istics ▁A ▁full ▁moon ▁is ▁often ▁thought ▁of ▁as ▁an ▁event ▁of ▁a ▁full ▁night ' s ▁duration . ▁This ▁is ▁somewhat ▁mis leading ▁because ▁its ▁phase ▁seen ▁from ▁Earth ▁continu ously ▁w ax es ▁or ▁w anes ▁( though ▁much ▁too ▁slowly ▁to ▁notice ▁in ▁real ▁time ▁with ▁the ▁n aked ▁eye ). ▁By ▁definition , ▁its ▁maximum ▁ill um ination ▁occurs ▁at ▁the ▁moment ▁w ax ing ▁stops . ▁For ▁any ▁given ▁location , ▁about ▁half ▁of ▁these ▁maximum ▁full ▁mo ons ▁may ▁be ▁visible , ▁while ▁the ▁other ▁half ▁occurs ▁during ▁the ▁day , ▁when ▁the ▁full ▁moon ▁is ▁below ▁the ▁horizon . ▁ ▁Many ▁al man acs ▁list ▁full ▁mo ons ▁not ▁only ▁by ▁date , ▁but ▁also ▁by ▁their ▁exact ▁time , ▁usually ▁in ▁Co ordin ated ▁Universal ▁Time ▁( UTC ). ▁Typ ical ▁month ly ▁cal end ars ▁that ▁include ▁lun ar ▁phases ▁may ▁be ▁offset ▁by ▁one ▁day ▁when ▁prepared ▁for ▁a ▁different ▁time ▁zone . ▁ ▁The ▁full ▁moon ▁is ▁generally ▁a ▁sub opt imal ▁time ▁for ▁astronom ical ▁observation ▁of ▁the ▁Moon ▁because ▁sh adows ▁van ish . ▁It ▁is ▁a ▁poor ▁time ▁for ▁other ▁observations ▁because ▁the ▁bright ▁sun light ▁reflected ▁by ▁the ▁Moon , ▁ampl ified ▁by ▁the ▁opposition ▁sur ge , ▁then ▁out sh ines ▁many ▁stars . ▁ ▁On ▁ 1 2 ▁December ▁ 2 0 0 8 , ▁the ▁full ▁moon ▁was ▁closer ▁to ▁the ▁Earth ▁than ▁it ▁had ▁been ▁at ▁any ▁time