Ji̍t-thâu nî

1 ê Ji̍t-thâu nî (tropical year) tō sī lán ùi Tē-kiû khoàⁿ Ji̍t-thâu se̍h n̂g-tō 1 lìn khai ê sî-kan. Cheng-khak ê sî-kan tio̍h khoàⁿ ùi toh 1 tiám khai-sí sǹg, lán phó͘-thong lóng sī ùi chhun-hun (vernal equinox) khí-sǹg, án-ne ê 1 ê Ji̍t-thâu nî tō sī chhun-hun nî (vernal equinox year); nā ēng só͘-ū ê tiám khí-sǹg chiah koh chhé-ûn, án-ne ê 1 ê Ji̍t-thâu nî tō sī pêng-kin Ji̍t-thâu nî (mean tropical year).