dayjs 常用方法总结

"YYYY-MM-DD HH:mm:ss

自定义解析日期

const customDate = dayjs("2025-08-18", "YYYY-MM-DD");
console.log("自定义解析日期:", customDate.format("YYYY-MM-DD"));

const customDate2 = dayjs("2025-08-18");
console.log("自定义解析日期:", customDate2.format("YYYY-MM-DD"));

当前日期

const today = dayjs();
console.log("当前日期:", today.format("YYYY-MM-DD"));

当前月份的第一天

const firstDayOfMonth = today.startOf("month");
console.log("当前月份的第一天:", firstDayOfMonth.format("YYYY-MM-DD"));

当前月份的最后一天

const lastDayOfMonth = today.endOf("month");
console.log("当前月份的最后一天:", lastDayOfMonth.format("YYYY-MM-DD"));

减去一天

const yesterday = today.subtract(1, "day");
console.log("昨天:", yesterday.format("YYYY-MM-DD"));

加上一天

const tomorrow = today.add(1, "day");
console.log("明天:", tomorrow.format("YYYY-MM-DD"));

减去一年

const lastYear = today.subtract(1, "year");
console.log("去年的今天:", lastYear.format("YYYY-MM-DD"));

加上一年

const nextYear = today.add(1, "year");
console.log("明年的今天:", nextYear.format("YYYY-MM-DD"));

获取星期几（0 = 周日，1 = 周一，...，6 = 周六）

const dayOfWeek = today.day();
console.log("今天是星期几:", dayOfWeek);

获取ISO周数

const isoWeekNumber = today.isoWeek();
console.log("当前ISO周数:", isoWeekNumber);

获取当前季度的第一天和最后一天

const firstDayOfQuarter = today.startOf("quarter");
const lastDayOfQuarter = today.endOf("quarter");
console.log("当前季度的第一天:", firstDayOfQuarter.format("YYYY-MM-DD"));
console.log("当前季度的最后一天:", lastDayOfQuarter.format("YYYY-MM-DD"));

获取当前年份的第一天和最后一天

const firstDayOfYear = today.startOf("year");
const lastDayOfYear = today.endOf("year");
console.log("当前年份的第一天:", firstDayOfYear.format("YYYY-MM-DD"));
console.log("当前年份的最后一天:", lastDayOfYear.format("YYYY-MM-DD"));

获取当前周的第一天和最后一天

const firstDayOfWeek = today.startOf("week");
const lastDayOfWeek = today.endOf("week");
console.log("当前周的第一天:", firstDayOfWeek.format("YYYY-MM-DD"));
console.log("当前周的最后一天:", lastDayOfWeek.format("YYYY-MM-DD"));