We quantify time by the way things rotate . It take one day for the Earth to spin one full rotation on its own bloc . It drive a small less than 28 days for the moonshine to spread out once around the Earth . It take a petty more than 365 twenty-four hour period for the Earth to go around the sunshine . It would be courteous if all this rotate was perfectly synced up , but it is n’t , and since we ca n’t curb the motions of the planets , we are stuck with a messy calendar organisation that needs a bit of adjusting now and then .
Leap years are one direction we correct for mismatches . Having months of variegate distance is another . In the calendar we use , the calendar month are only roughly inspire by moon cycles . If we measured months by the moon and the yr by the sun , the seasons would start to drift and finally the Fourth of July would be in the dead of wintertime .
The Hebrew calendar , used to determine the dates of Jewish holidays , stick to the cycles of the moon more closely . month are 29 or 30 day , but complicated adjustments are made , include the accession of an spare calendar month every so often , for ensure that sealed holidays show up in the correct season . Hanukkah is supposed to bulge on the 25th of Kislev , which after movement and alteration , ends up falling between the end of November and the end of December . This year it ’s on November 28th , the early particular date it can be , which also happens to be Thanksgiving .
The 25th of Kislev will fall on November 28th again , but not when November 28th is also Thanksgiving ( quaternary Thursday of the month ) . Also , there is a flyspeck difference in the manner adjustments to align the seasons are made in the two calendar , so tiny that they only matter after they cumulate for a few hundred twelvemonth . By the fourth dimension enough years have passed to get to the point where Hanukkah would flow on a November 28th that was also Thanksgiving again , that tiny divergence will have pushed Hanukkah over the line to the next daylight . And there ’s no go back to the early date . The early particular date for Hanukkah will slowly keep getting later …
… unless another fully grown adjustment by decree is made , which is what has happen every couple thousand years in the account of calendar keeping . If Hanukkah and Thanksgiving coincide again , it wo n’t be according to the systems as they are in place now , but through our improvised endeavor to keep up with the sloppy , syncopate spinning of the heavens .
If you need more specific item on the adjustments , hereis a more in - depth explanation of the number .
