Sikusare
| Tukio | Sikusare | Solistasi | Sikusare | Solistasi | ||||
|---|---|---|---|---|---|---|---|---|
| Mwezi | Machi | Juni | Septemba | Disemba | ||||
| Mwaka | ||||||||
| Siku | Saa | Siku | Saa | Siku | Saa | Siku | Saa | |
| 2018 | 20 | 16:15 | 21 | 10:07 | 23 | 01:54 | 21 | 22:23 |
| 2019 | 20 | 21:58 | 21 | 15:54 | 23 | 07:50 | 22 | 04:19 |
| 2020 | 20 | 03:50 | 20 | 21:44 | 22 | 13:31 | 21 | 10:02 |
| 2021 | 20 | 09:37 | 21 | 03:32 | 22 | 19:21 | 21 | 15:59 |
| 2022 | 20 | 15:33 | 21 | 09:14 | 23 | 01:04 | 21 | 21:48 |
| 2023 | 20 | 21:24 | 21 | 14:58 | 23 | 06:50 | 22 | 03:27 |
| 2024 | 20 | 03:07 | 20 | 20:51 | 22 | 12:44 | 21 | 09:20 |
Sikusare (pia: siku mlingano au ikwinoksi kutoka Kilatini na Kiingereza equinox; [3]) ni siku ambako urefu wa mchana na usiku ni sawa kote duniani.
Hii inatokea mara mbili kila mwaka, mara ya kwanza mnamo 21 Machi (sikusare machipuo) na 23 Septemba (sikusare otomnia).
Katika kanda karibu na ikweta hazionekani kwa urahisi lakini kwenye nusutufe za dunia upande wa kusini na kaskazini wa ikweta zimetambuliwa tangu karne nyingi na zimekuwa siku muhimu kwa makadirio ya kalenda mbalimbali.
Kwa kawaida kuna tofauti kati ya urefu wa mchana na usiku isipokuwa karibu na ikweta. Karibu na ncha za dunia muda wa usiku na mchana unaweza kuwa mrefu hadi karibu nusu mwaka lakini kwa kawaida kuna majira ya mchana mrefu na usiku mrefu zinazobadilishana polepole.
Kuanzia usawa wa mchana na usiku kwenye sikusare muda wa mchana unarefuka au kupungua polepole kati ya kufikia ama siku ya mchana mrefu au usiku mrefu unaotokea katikati ya sikusare mbili za mwaka halafu mwendo hutokea kinyume hadi kufikia sikusare tena.
Mwendo huo unatokea kinyume kwenye nusutufe mbili za dunia yaani wakati mchana unarefuka kwenye nusutufe ya kaskazini usiku unarefuka kwenye nusutufe ya kusini.
Marejeo
Viungo vya nje
- Details about the Length of Day and Night at the Equinoxes Archived 17 Septemba 2020 at the Wayback Machine.. U.S. Naval Observatory. Naval Meteorology and Oceanography Command
- Calculation of Length of Day (Formulas and Graphs)
- Equinoctial Points — The Nuttall Encyclopædia
- Table of times for Equinoxes, Solstices, Perihelion and Aphelion in 2000–2020 Archived 22 Agosti 2014 at the Wayback Machine.
- Table of times of Spring Equinox for a thousand years: 1452–2547 Archived 29 Septemba 2007 at the Wayback Machine.
- "Ancient Equinox Alignment". Loughcrew, Ireland * Lady Day: The Vernal Equinox * Archaeological sites with connections to the Equinox * The Autumn Equinox in world mythology and spirituality.