def Date.to_z.at
import bend-kit-time@0.3.0.0/time.bend as Timeimport Base
209def Date.to_z.at(+y: U32, +mp: U32, +d: U32) -> U32:
210 +era = (y / 400 : U32)
211 +yoe = (y - era * 400 : U32)
212 +doy = ((153 * mp + 2) / 5 + d - 1 : U32)
213 (era * 146097 + yoe * 365 + yoe / 4 - yoe / 100 + doy : U32)