date-manip

---

date-manip / startOf

startOf

函数

default()

default(date, unit): Date

定义于: src/startOf.ts:53

Sets the date to the start of the specified unit of time. 将日期设置为指定时间单位的开始时间。

参数

date

Date

The date to set to the start of the specified unit. (要设置为指定时间单位开始时间的日期。)

unit

Unit

The unit of time to set the start of (e.g., 'year', 'month', 'day', 'hour', 'minute', 'second'). (要设置开始时间的时间单位，例如 'year'、'month'、'day'、'hour'、'minute'、'second'。)

返回

Date

A new date object set to the start of the specified unit. (设置为指定时间单位开始时间的新日期对象。)

示例

// Setting the start of the year (设置年份开始时间)
const date1 = new Date('2023-10-01');
const startOfYear = startOf(date1, 'year');
console.log(startOfYear.toISOString()); // Outputs: '2023-01-01T00:00:00.000Z' (输出: '2023-01-01T00:00:00.000Z')

// Setting the start of the month (设置月份开始时间)
const date2 = new Date('2023-10-01');
const startOfMonth = startOf(date2, 'month');
console.log(startOfMonth.toISOString()); // Outputs: '2023-10-01T00:00:00.000Z' (输出: '2023-10-01T00:00:00.000Z')

// Setting the start of the day (设置天数开始时间)
const date3 = new Date('2023-10-01T12:30:45');
const startOfDay = startOf(date3, 'day');
console.log(startOfDay.toISOString()); // Outputs: '2023-10-01T00:00:00.000Z' (输出: '2023-10-01T00:00:00.000Z')

// Setting the start of the hour (设置小时开始时间)
const date4 = new Date('2023-10-01T12:30:45');
const startOfHour = startOf(date4, 'hour');
console.log(startOfHour.toISOString()); // Outputs: '2023-10-01T12:00:00.000Z' (输出: '2023-10-01T12:00:00.000Z')

// Setting the start of the minute (设置分钟开始时间)
const date5 = new Date('2023-10-01T12:30:45');
const startOfMinute = startOf(date5, 'minute');
console.log(startOfMinute.toISOString()); // Outputs: '2023-10-01T12:30:00.000Z' (输出: '2023-10-01T12:30:00.000Z')

// Setting the start of the second (设置秒数开始时间)
const date6 = new Date('2023-10-01T12:30:45.678');
const startOfSecond = startOf(date6, 'second');
console.log(startOfSecond.toISOString()); // Outputs: '2023-10-01T12:30:45.000Z' (输出: '2023-10-01T12:30:45.000Z')