2月29日几年有一次(闰年的特殊一天)
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闰年的特殊一天
WhatisaLeapYear?
February29thonlyoccursonceeveryfouryears,makingitaspecialday.ThisdayiscalledLeapDayandtheyearitoccursiniscalledaLeapYear.
ThereasonforthisspecialdayisduetothefactthattheEarth'sorbitaroundthesunisnotexactly365days.Itisactually365.2422days.Thismaynotseemlikemuch,butovertimeitaddsup.Toaccountforthisdiscrepancy,anextradayisaddedtothecalendareveryfouryears.
TheHistoryofLeapYear
TheconceptofLeapYeardatesbacktoancienttimes.JuliusCaesarfirstintroducedLeapYearintheRomancalendarin45BCE.However,thissystemwasnotperfectandovertime,thecalendarfelloutofsyncwiththeseasons.In1582,PopeGregoryXIIIintroducedtheGregoriancalendarwhichisthecalendarwestillusetoday.
TheGregoriancalendardeterminesLeapYearasfollows:ayearisaLeapYearifitisdivisiblebyfour,unlessitisdivisibleby100butnot400.Thismayseemcomplicated,butitensuresthatthecalendarstaysinalignmentwiththeEarth'sorbit.
CelebratingLeapDay
LeapDayisaspecialdaythatonlyoccursonceeveryfouryears.Itisadaytocelebratetherarityoftheeventandtomakethemostoftheextradaywereceive.SomepeoplechoosetohaveLeapDay-themedpartiesorgatheringstomarktheoccasion.Othersusethedaytodosomethingspecialortotrysomethingnew.
IfyouwerebornonLeapDay,youarepartofauniquegroupofpeoplecalledLeaplings.Yourbirthdayonlyoccursonceeveryfouryears,soyoumaychoosetocelebrateonFebruary28thorMarch1stinnon-LeapYears.
LeapDayisareminderthattimeispreciousandthatweshouldmakethemostofeverymoment.So,whetheryouchoosetocelebratethedayornot,takeamomenttoappreciatetherarityoftheoccasionandtocherishthetimeyouhave.