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# 时间相关

记录时间日期相关的功能，方便查阅

# 检查日期是否为周末


const isWeekend = (date) => [0, 6].indexOf(date.getDay()) !== -1;
console.log(isWeekend(new Date(2021, 4, 14)));
// false (Friday)
console.log(isWeekend(new Date(2021, 4, 15)));
// true (Saturday)

# 计算两个日期之间的天数


const daysDiff = (date, date2) => Math.ceil(Math.abs(date - date2) / 86400000);

console.log(daysDiff(new Date('2021-05-10'), new Date('2021-11-25')));
// 199

# 检查日期是否合法


const isDateValid = (...val) => !Number.isNaN(new Date(...val).valueOf());
isDateValid("December 17, 1995 03:24:00");
// Result: true

# 查找日期位于一年中的第几天


const dayOfYear = (date) =>Math.floor((date - new Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24);
dayOfYear(new Date());
// Result: 272

# 时间格式化处理


//从给定日期以 hour::minutes::seconds 格式记录时间
const timeFromDate = date => date.toTimeString().slice(0, 8);
console.log(timeFromDate(new Date(2021, 0, 10, 17, 30, 0))); 
// Result: "17:30:00"

格式化时间 2


export const dateFormater = (formater, time) => {
    let date = time ? new Date(time) : new Date(),
        Y = date.getFullYear() + '',
        M = date.getMonth() + 1,
        D = date.getDate(),
        H = date.getHours(),
        m = date.getMinutes(),
        s = date.getSeconds();
    return formater.replace(/YYYY|yyyy/g, Y)
        .replace(/YY|yy/g, Y.substr(2, 2))
        .replace(/MM/g,(M<10 ? '0' : '') + M)
        .replace(/DD/g,(D<10 ? '0' : '') + D)
        .replace(/HH|hh/g,(H<10 ? '0' : '') + H)
        .replace(/mm/g,(m<10 ? '0' : '') + m)
        .replace(/ss/g,(s<10 ? '0' : '') + s)
}
// dateFormater('YYYY-MM-DD HH:mm:ss')
// dateFormater('YYYYMMDDHHmmss')

# 当前时间


export const nowTime = () => {
    const now = new Date();
    const year = now.getFullYear();
    const month = now.getMonth();
    const date = now.getDate() >= 10 ? now.getDate() : ('0' + now.getDate());
    const hour = now.getHours() >= 10 ? now.getHours() : ('0' + now.getHours());
    const miu = now.getMinutes() >= 10 ? now.getMinutes() : ('0' + now.getMinutes());
    const sec = now.getSeconds() >= 10 ? now.getSeconds() : ('0' + now.getSeconds());
    return +year + "年" + (month + 1) + "月" + date + "日 " + hour + ":" + miu + ":" + sec;
}

# 判断日期是否正确


//此方法用于检查给定日期是否有效。
const isDateValid = (...val) => !Number.isNaN(new Date(...val).valueOf());
isDateValid("December 27, 2022 13:14:00");  // true

# 生成 UNIX 时间戳


const getTimestamp = (date = new Date()) => Math.floor(date.getTime() / 1000);
getTimestamp(); // 160216224

# 检查某个日期是否在另一个日期之后


const isAfterDate = (dateA, dateB) => dateA > dateB;
isAfterDate(new Date(2010, 10, 21), new Date(2010, 10, 20)); // true

# 两个日期是否相等


const isSameDate = (dateA, dateB) => dateA.toISOString() === dateB.toISOString();
isSameDate(new Date(2010, 10, 20), new Date(2010, 10, 20)); // true

# 获取最新/大日期


const maxDate = (...dates) => new Date(Math.max.apply(null, ...dates));

const array = [
  new Date(2017, 4, 13),
  new Date(2018, 2, 12),
  new Date(2016, 0, 10),
  new Date(2016, 0, 9)
];
maxDate(array); // 2018-03-11T22:00:00.000Z

最早日期


const minDate = (...dates) => new Date(Math.min.apply(null, ...dates));

const array = [
  new Date(2017, 4, 13),
  new Date(2018, 2, 12),
  new Date(2016, 0, 10),
  new Date(2016, 0, 9)
];
minDate(array); // 2016-01-08T22:00:00.000Z
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