Ngezinye izikhathi uFebhuwari uba nesimo esikhangayo ngendlela engavamile ekhalendeni. Isibonelo, ngoFebhuwari 2021, umuntu angase abhekane "noFebhuwari oyisikwele ngokuphelele." Lo mphumela ongavamile uyenzeka lapho uFebhuwari enezinsuku ezingama \(28\) kanye noFebhuwari 1 ungoMsombuluko. Kodwa lokhu kwenzeka kangaki ngempela, futhi kufanele silinde isikhathi esingakanani ukuze sifike 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.:
Ngakho-ke ekhalendeni likaGregory kukhona \(14\) izinhlobo zekhalenda ezingaba khona: eziyisikhombisa zeminyaka engagxumi ( \(365\) izinsuku), lapho u-January 1st uba ngosuku oluhlukile lwesonto, kanye nesikhombisa iminyaka ye-leap \(366\) izinsuku), lapho uJanuwari 1 ewela ngosuku oluhlukile lwesonto.
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 sisho \(366\) -ikhalenda yosuku lapho uJanuwari 1st eba ngoMsombuluko ngokuthi \(1\) , ukuthi ngoLwesibili njengo \(2\) , 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 uhlala unezinsuku ezingu \(31\) , futhi sifuna uFebhuwari aqale ngoMsombuluko. Lokhu kusho ukuthi uJanuwari 31 kumele awele ngeSonto. Uma uJanuwari 24, 17, 10, kanye no-3 kuyiSonto, khona-ke uJanuwari 1 uwela ngoLwesihlanu. Ngakho-ke, sifuna ikhalenda \(E\) Ikhalenda \(5\) alikwazi ukusetshenziswa ngoba liyikhalenda lonyaka oqavile elinezinsuku ezingu \(29\) kuFebhuwari.
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 \(400\) .
Uchungechunge lwekhalenda emjikelezweni weminyaka engu \(400\) lubukeka kanje::
$$\displaylines{ABC4 \,\, FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3\\
EFG1 \,\, CDE6 \,\, ABC4 \,\, FGA2 \,\, DEF7\\
BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6 \,\, ABC4\\
FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1\\
CDE6 \,\, ABC4 \,\, FGA2 \,\, DEF7 \,\, BCDE\\
FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1\\
CDE6 \,\, ABC4 \,\, FGA2 \,\, DEF7 \,\, BCD5\\
GAB3 \,\, EFG1 \,\, CDE6 \,\, ABC4 \,\, FGA2\\
DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6\\
ABC4 \,\, FGA2 \,\, DEF7 \,\, BCD5 \,\, GABC\\
DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6\\
ABC4 \,\, FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3\\
EFG1 \,\, CDE6 \,\, ABC4 \,\, FGA2 \,\, DEF7\\
BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6 \,\, ABC4\\
FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3 \,\, EFGA\\
BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6 \,\, ABC4\\
FGA2 \,\, DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1\\
CDE6 \,\, ABC4 \,\, FGA2 \,\, DEF7 \,\, BCD5\\
GAB3 \,\, EFG1 \,\, CDE6 \,\, ABC4 \,\, FGA2\\
DEF7 \,\, BCD5 \,\, GAB3 \,\, EFG1 \,\, CDE6}$$
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.