function getBeginningOfMonthimport { getBeginningOfMonth } from "https://deno.land/x/somefn@v0.1.1-jsr/js/date.ts"; getBeginningOfMonth(v: Date | MonthString, opt?: { timezone?: string; }): MillisecondTimestamp获取月初时间 Parametersv: Date | MonthString支持 Date 和 202101... 这样的字符串 optionalopt: { timezone?: string; } = [UNSUPPORTED]ReturnsMillisecondTimestamp月初时间的毫秒时间戳