<\/div>\n
T\u1ea1i sao c\u00f3 ng\u00e0y nhu\u1eadn ?<\/h3>\n
\u0110\u1ec3 tr\u1ea3 l\u1eddi c\u00e2u h\u1ecfi n\u00e0y ph\u1ea3i d\u1ef1a v\u00e0o ki\u1ebfn th\u1ee9c khoa h\u1ecdc. M\u1ecdi ng\u01b0\u1eddi \u0111\u1ec1u bi\u1ebft Tr\u00e1i \u0111\u1ea5t m\u1ea5t 365 ng\u00e0y \u0111\u1ec3 \u0111i h\u1ebft 1 v\u00f2ng quanh M\u1eb7t tr\u1eddi (k\u1ebft th\u00fac 1 n\u0103m). Nh\u01b0ng tr\u00ean th\u1ef1c t\u1ebf th\u00ec 1 v\u00f2ng \u0111\u00f3 c\u00f3 th\u1eddi gian ch\u00ednh x\u00e1c l\u00e0 365 ng\u00e0y 5 gi\u1edd 48 ph\u00fat 46 gi\u00e2y, t\u1ee9c l\u00e0 365.25 ng\u00e0y.<\/p>\n
Ph\u1ea7n d\u01b0 0,25 ng\u00e0y \u0111\u00f3 sau 4 n\u0103m s\u1ebd t\u00edch l\u1ea1i th\u00e0nh 1 ng\u00e0y, ch\u00ednh l\u00e0 ng\u00e0y nhu\u1eadn. V\u00e0 c\u1ee9 4 n\u0103m s\u1ebd s\u1edf h\u1eefu m\u1ed9t n\u0103m 366 ng\u00e0y g\u1ecdi l\u00e0 n\u0103m nhu\u1eadn. \u0110\u00f3 l\u00e0 l\u00fd do t\u1ea1i sao n\u0103m nhu\u1eadn c\u00f3 366 ng\u00e0y. Ng\u00e0y nhu\u1eadn d\u01b0 ra m\u1ed7i 4 n\u0103m 1 l\u1ea7n \u0111\u00f3 \u0111\u01b0\u1ee3c t\u00ednh v\u00e0o th\u00e1ng 2, s\u1ebd c\u00f3 th\u00eam m\u1ed9t ng\u00e0y nhu\u1eadn l\u00e0 ng\u00e0y 29\/2 ch\u1ee9 kh\u00f4ng ph\u1ea3i ch\u1ec9 c\u00f3 28 ng\u00e0y nh\u01b0 c\u0169 n\u1eefa.<\/p>\n
C\u00e1ch t\u00ednh ng\u00e0y th\u00e1ng n\u0103m nhu\u1eadn ch\u00ednh x\u00e1c<\/h2>\n
Sau gi\u1ea3i \u0111\u00e1p t\u1ea1i sao c\u00f3 ng\u00e0y nhu\u1eadn th\u00ec c\u00e1ch t\u00ednh n\u0103m nhu\u1eadn, l\u00e0m sao nh\u1eadn bi\u1ebft \u0111\u01b0\u1ee3c n\u0103m nhu\u1eadn c\u0169ng r\u1ea5t quan tr\u1ecdng. H\u00e3y t\u00ecm hi\u1ec3u c\u00e1ch t\u00ednh ch\u00ednh x\u00e1c theo c\u1ea3 d\u01b0\u01a1ng l\u1ecbch v\u00e0 \u00e2m l\u1ecbch nh\u00e9.<\/p>\n
C\u00e1ch t\u00ednh theo d\u01b0\u01a1ng l\u1ecbch<\/h3>\n
R\u1ea5t d\u1ec5 d\u00e0ng \u0111\u1ec3 nh\u1eadn bi\u1ebft \u0111\u01b0\u1ee3c n\u0103m n\u00e0o l\u00e0 n\u0103m nhu\u1eadn theo D\u01b0\u01a1ng l\u1ecbch. N\u1ebfu s\u1ed1 bi\u1ec3u n\u0103m \u0111\u00f3 chia h\u1ebft cho 4 th\u00ec n\u0103m \u0111\u00f3 l\u00e0 n\u0103m nhu\u1eadn. V\u00ed d\u1ee5: 1996, 2000, 2004,..<\/p>\n
Nh\u01b0ng c\u00f3 nh\u1eefng tr\u01b0\u1eddng h\u1ee3p ngo\u1ea1i l\u1ec7 l\u00e0 nh\u1eefng n\u0103m tr\u00f2n Th\u1ebf k\u1ef7 (c\u00f3 2 s\u1ed1 0 \u1edf cu\u1ed1i nh\u01b0 1700, 1800, 1900,vv…) th\u00ec ta ph\u1ea3i t\u00ednh d\u1ef1a v\u00e0o 2 con s\u1ed1 \u0111\u1ea7u. N\u1ebfu chia v\u1eeba \u0111\u1ee7 cho 4 th\u00ec n\u0103m \u0111\u00f3 c\u00f3 nhu\u1eadn. V\u00ed d\u1ee5 1600 l\u00e0 n\u0103m nhu\u1eadn v\u00ec 16 chia h\u1ebft cho 4, t\u01b0\u01a1ng t\u1ef1 1700 kh\u00f4ng ph\u1ea3i n\u0103m nhu\u1eadn v\u00ec 17 kh\u00f4ng chia h\u1ebft cho 4.<\/p>\n