常规
1. dayOfYear（已过天数）
FROM
30 seconds of code (Date) (opens new window)
FUNCTION：
const dayOfYear = date =>
Math.floor((date - new Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24);
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EXAMPLES：
dayOfYear(new Date()); // 272
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2. formatDuration（格式化毫秒）
FROM
30 seconds of code (Date) (opens new window)
FUNCTION：
const formatDuration = ms => {
if (ms < 0) ms = -ms;
const time = {
day: Math.floor(ms / 86400000),
hour: Math.floor(ms / 3600000) % 24,
minute: Math.floor(ms / 60000) % 60,
second: Math.floor(ms / 1000) % 60,
millisecond: Math.floor(ms) % 1000
};
return Object.entries(time)
.filter(val => val[1] !== 0)
.map(([key, val]) => `${val} ${key}${val !== 1 ? 's' : ''}`)
.join(', ');
};
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EXAMPLES：
formatDuration(1001); // '1 second, 1 millisecond'
formatDuration(34325055574); // '397 days, 6 hours, 44 minutes, 15 seconds, 574 milliseconds'
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3. getColonTimeFromDate（time）
FROM
30 seconds of code (Date) (opens new window)
FUNCTION：
const getColonTimeFromDate = date => date.toTimeString().slice(0, 8);
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EXAMPLES：
getColonTimeFromDate(new Date()); // "08:38:00"
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3. getDaysDiffBetweenDates（天数间隔）
FROM
30 seconds of code (Date) (opens new window)
FUNCTION：
const getDaysDiffBetweenDates = (dateInitial, dateFinal) =>
(dateFinal - dateInitial) / (1000 * 3600 * 24);
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EXAMPLES：
getDaysDiffBetweenDates(new Date('2017-12-13'), new Date('2017-12-22')); // 9
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4. getMeridiemSuffixOfInteger（am/pm）
FROM
30 seconds of code (Date) (opens new window)
FUNCTION：
const getMeridiemSuffixOfInteger = num =>
num === 0 || num === 24
? 12 + 'am'
: num === 12
? 12 + 'pm'
: num < 12
? (num % 12) + 'am'
: (num % 12) + 'pm';
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EXAMPLES：
getMeridiemSuffixOfInteger(0); // "12am"
getMeridiemSuffixOfInteger(11); // "11am"
getMeridiemSuffixOfInteger(13); // "1pm"
getMeridiemSuffixOfInteger(25); // "1pm"
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5. isBeforeDate/isAfterDate/isSameDate
FROM
30 seconds of code (Date) (opens new window)
FUNCTION：
const isBeforeDate = (dateA, dateB) => dateA < dateB;
const isAfterDate = (dateA, dateB) => dateA > dateB;
const isSameDate = (dateA, dateB) => dateA.toISOString() === dateB.toISOString();
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EXAMPLES：
isBeforeDate(new Date(2010, 10, 20), new Date(2010, 10, 21)); // true
isAfterDate(new Date(2010, 10, 21), new Date(2010, 10, 20)); // true
isSameDate(new Date(2010, 10, 20), new Date(2010, 10, 20)); // true
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6. isLeapYear（闰年）
FROM
30 seconds of code (Date) (opens new window)
DETAIL：
没想到判断闰年还能这么操作。
FUNCTION：
const isLeapYear = year => new Date(year, 1, 29).getMonth() === 1;
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EXAMPLES：
isBeforeDate(new Date(2010, 10, 20), new Date(2010, 10, 21)); // true
isAfterDate(new Date(2010, 10, 21), new Date(2010, 10, 20)); // true
isSameDate(new Date(2010, 10, 20), new Date(2010, 10, 20)); // true
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7. isWeekday/isWeekend
FROM
30 seconds of code (Date) (opens new window)
FUNCTION：
const isWeekday = (t = new Date()) => {
return t.getDay() % 6 !== 0;
};
const isWeekend = (t = new Date()) => {
return t.getDay() % 6 === 0;
};
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EXAMPLES：
isWeekday(); // true (if current date is 2019-07-19)
isWeekend(); // 2018-10-19 (if current date is 2018-10-18)
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8. minDate/maxDate
FROM
30 seconds of code (Date) (opens new window)
DETAIL：
Math 配合展开符的常见操作。
FUNCTION：
const minDate = dates => new Date(Math.min(...dates));
const maxDate = dates => new Date(Math.max(...dates));
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EXAMPLES：
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
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
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8. yesterday/tomorrow
FROM
30 seconds of code (Date) (opens new window)
DETAIL：
Math 配合展开符的常见操作。
FUNCTION：
const yesterday = () => {
let t = new Date();
t.setDate(t.getDate() - 1);
return t.toISOString().split('T')[0];
};
const tomorrow = () => {
let t = new Date();
t.setDate(t.getDate() + 1);
return t.toISOString().split('T')[0];
};
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EXAMPLES：
yesterday(); // 2018-10-17 (if current date is 2018-10-18)
tomorrow(); // 2018-10-19 (if current date is 2018-10-18)
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