Ngezinye izikhathi u-February uba nesimo esikhanga ngendlela engavamile ekhalendeni. Isibonelo, ngoFebhuwari 2021 umuntu angathola umzuzu onjalo, ebona "uFebhuwari ononxande". Lo mphumela ongavamile uvela lapho uFebruwari enezinsuku \(28\) ncamashi futhi uFebruwari 1 uba ngoMsombuluko. Kodwa lokhu kwenzeka kangaki ngempela futhi kufanele ulinde isikhathi esingakanani esikhathini esizayo?
Ukuze uFebhuwari abonakale "engunxande ngokuphelele," kufanele kuhlangatshezwane nemibandela emibili:
- Kufanele kube unyaka ongagxumi, ngakho uFebhuwari unezinsuku \(28\) ncamashi,
- UFebhuwari 1 kufanele ube ngoMsombuluko.
Uma zombili lezi zimo zihlangatshezwana nazo, uFebruwari ulingana ncamashí negridi \(4x7\) ekhalendeni, ngaphandle kwezinsuku ezisuka kwezinye izinyanga ezivela evikini elifanayo.:
Ekhalendeni likaGregory kukhona \(14\) izinhlobo zekhalenda ezingaba khona: eziyisikhombisa zeminyaka engagxumi ( \(365\) izinsuku), lapho uJanuwari 1 eba ngosuku oluhlukile lwesonto kanye nesikhombisa iminyaka ye-leap. \(366\) izinsuku) lapho uJanuwari 1 ephinde abe ngosuku oluhlukile lweviki.
Ake sithi sisho \(365\) ikhalenda losuku lapho uJanuwari 1st eba ngoMsombuluko ngokuthi \(A\) . Ikhalenda lapho unyaka uqala khona ngoLwesibili lithi \(B\) , ukuthi ngolwesithathu ngu \(C\) njalo kuze kube \(G\) . Bese sibheka \(366\) -amakhalenda wezinsuku lapho u-January 1st eba ngoMsombuluko ngokuthi \(1\) , ukuthi ngoLwesibili ngokuthi \(2\) , njalonjalo. Lokhu kubangela amakhalenda alandelayo ayi-14 ahlukene:
- Izinsuku ezingama-365: \(A, B, C, D, E, F, G\)
- Izinsuku ezingama-366 (iminyaka ye-leap): \(1, 2, 3, 4, 5, 6, 7\)
Manje uJanuwari uhlale unezinsuku \(31\) , futhi sifuna ukuthi uFebruwari aqale ngoMsombuluko. Lokhu kusho ukuthi uJanuwari 31 kumele ube ngeSonto. Uma uJanuwari 24, 17, 10 no-3 kungamasonto, khona-ke uJanuwari 1 uba ngoLwesihlanu. Ngakho sibheka ikhalenda \(E\) . Ikhalenda \(5\) alinakusetshenziswa ngoba lena iminyaka ye-leap lapho u-February enezinsuku \(29\) .
Ikhalenda lilandela umjikelezo wonyaka \(400\) wonyaka. Kukhona \(97\) iminyaka ye-leap kulo mjikelezo, futhi usuwonke umjikelezo uhlanganisa \(146.097\) izinsuku. Khona-ke umjikelezo uqala futhi. Ngo \(2001\) umjikelezo omusha waqala futhi uJanuwari 1 waba ngoMsombuluko. Onyakeni ojwayelekile wezinsuku \(365\) , unyaka omusha uhlala uqala ngosuku olulandelayo lweviki uma kuqhathaniswa nonyaka odlule. Nokho, ngemva konyaka we-leap, unyaka omusha uqala ngemva kwezinsuku ezimbili. UJanuwari 1, 2001 kwakunguMsombuluko, 2002 ngoLwesibili, 2003 ngoLwesithathu, 2004 ngoLwesine nango-2005 ngoMgqibelo. Ayikho iminyaka ye-leap eminyakeni eyikhulu ngaphandle uma unyaka wekhulu uhlukaniswa ngokuthi \(400\) .
Ukulandelana kwekhalenda emjikelezweni wonyaka \(400\) kungokulandelayo:
$$\displaylines{ABC4 \,\, FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3\\
EFG1 \,\, CDE6 \,\, ABC4 \,\, FGA2 \,\, DEF7\\
BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6 \,\, ABC4\\
FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1\\
CDE6 \,\, ABC4 \,\, FGA2 \,\, DEF7 \,\, BCDE\\
FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1\\
CDE6 \,\, ABC4 \,\, FGA2 \,\, DEF7 \,\, BCD5\\
GAB3 \,\, EFG1 \,\, CDE6 \,\, ABC4 \,\, FGA2\\
DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6\\
ABC4 \,\, FGA2 \,\, DEF7 \,\, BCD5 \,\, GABC\\
DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6\\
ABC4 \,\, FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3\\
EFG1 \,\, CDE6 \,\, ABC4 \,\, FGA2 \,\, DEF7\\
BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6 \,\, ABC4\\
FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3 \,\, EFGA\\
BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6 \,\, ABC4\\
FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1\\
CDE6 \,\, ABC4 \,\, FGA2 \,\, DEF7 \,\, BCD5\\
GAB3 \,\, EFG1 \,\, CDE6 \,\, ABC4 \,\, FGA2\\
DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6}$$
Manje okumele sikwenze ukubala ukuthi ikhalenda \(E\) livela kangaki kulokhu kulandelana. Kukhona \(43\) izehlakalo:
$$\frac{43}{400} = \frac{10,75}{100} = 10,75\%$$
Isikwele esiphelele sikaFebruwari kuyinto engavamile yekhalenda eyenzeka cishe kanye eminyakeni eyishumi. Ngakho-ke ngokuzayo lapho ubona ikhalenda elinoFebhruwari oyisikwele ngokuphelele, yazi ukuthi ubona isikhathi esiyivelakancane nesinhle esifika kanye njalo eminyakeni eyishumi noma ngaphezulu. Kodwa-ke, isikhathi esilandelayo sizokwenzeka ngoFebhuwari 2027.