charts/src/js/utils/date-utils.js
2020-12-14 15:25:39 +05:30

91 lines
2.5 KiB
JavaScript

// Playing around with dates
export const NO_OF_YEAR_MONTHS = 12;
export const NO_OF_DAYS_IN_WEEK = 7;
export const DAYS_IN_YEAR = 375;
export const NO_OF_MILLIS = 1000;
export const SEC_IN_DAY = 86400;
export const MONTH_NAMES = ["January", "February", "March", "April", "May",
"June", "July", "August", "September", "October", "November", "December"];
export const MONTH_NAMES_SHORT = ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
export const DAY_NAMES_SHORT = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];
export const DAY_NAMES = ["Sunday", "Monday", "Tuesday", "Wednesday",
"Thursday", "Friday", "Saturday"];
// https://stackoverflow.com/a/11252167/6495043
function treatAsUtc(date) {
let result = new Date(date);
result.setMinutes(result.getMinutes() - result.getTimezoneOffset());
return result;
}
export function getYyyyMmDd(date) {
let dd = date.getDate();
let mm = date.getMonth() + 1; // getMonth() is zero-based
return [
date.getFullYear(),
(mm > 9 ? '' : '0') + mm,
(dd > 9 ? '' : '0') + dd
].join('-');
}
export function clone(date) {
return new Date(date.getTime());
}
export function timestampSec(date) {
return date.getTime() / NO_OF_MILLIS;
}
export function timestampToMidnight(timestamp, roundAhead = false) {
let midnightTs = Math.floor(timestamp - (timestamp % SEC_IN_DAY));
if (roundAhead) {
return midnightTs + SEC_IN_DAY;
}
return midnightTs;
}
// export function getMonthsBetween(startDate, endDate) {}
export function getWeeksBetween(startDate, endDate) {
let weekStartDate = setDayToSunday(startDate);
return Math.ceil(getDaysBetween(weekStartDate, endDate) / NO_OF_DAYS_IN_WEEK);
}
export function getDaysBetween(startDate, endDate) {
let millisecondsPerDay = SEC_IN_DAY * NO_OF_MILLIS;
return (treatAsUtc(endDate) - treatAsUtc(startDate)) / millisecondsPerDay;
}
export function areInSameMonth(startDate, endDate) {
return startDate.getMonth() === endDate.getMonth()
&& startDate.getFullYear() === endDate.getFullYear();
}
export function getMonthName(i, short = false) {
let monthName = MONTH_NAMES[i];
return short ? monthName.slice(0, 3) : monthName;
}
export function getLastDateInMonth(month, year) {
return new Date(year, month + 1, 0); // 0: last day in previous month
}
// mutates
export function setDayToSunday(date) {
let newDate = clone(date);
const day = newDate.getDay();
if (day !== 0) {
addDays(newDate, (-1) * day);
}
return newDate;
}
// mutates
export function addDays(date, numberOfDays) {
date.setDate(date.getDate() + numberOfDays);
}