Calculate an expected delivery date (accounting for holidays) in business days using JavaScript?
Solution 1
Thanks for your input guys, I had a long hard re-think over the approach I was making for this and came up with this little number...
var businessDays = 7, counter = 0; // set to 1 to count from next business day
while( businessDays>0 ){
var tmp = new Date();
var startDate = new Date();
tmp.setDate( startDate .getDate() + counter++ );
switch( tmp.getDay() ){
case 0: case 6: break;// sunday & saturday
default:
businessDays--;
};
}
The idea was to start with the business days and count backwards to zero for each day encountered that fell in to the range of a business day. This use of switch would enable a person to declare a day in the week as a non-business day, for example someone may not work on a monday, therefore the addition of case:1 would include a monday.
This is a simple script and does not take in to account public or bank holidays, that would be asking for a much more complex script to work with.
The result is a date that is set to the date of shipping, the user can then extract the date info in any format that they please, eg.
var shipDate = tmp.toUTCString().slice(1,15);
Solution 2
I've adapted Mark Giblin's revised code to better deal with end of year dates and also U.S. federal holidays. See below...
function businessDaysFromDate(date,businessDays) {
var counter = 0, tmp = new Date(date);
while( businessDays>=0 ) {
tmp.setTime( date.getTime() + counter * 86400000 );
if(isBusinessDay (tmp)) {
--businessDays;
}
++counter;
}
return tmp;
}
function isBusinessDay (date) {
var dayOfWeek = date.getDay();
if(dayOfWeek === 0 || dayOfWeek === 6) {
// Weekend
return false;
}
holidays = [
'12/31+5', // New Year's Day on a saturday celebrated on previous friday
'1/1', // New Year's Day
'1/2+1', // New Year's Day on a sunday celebrated on next monday
'1-3/1', // Birthday of Martin Luther King, third Monday in January
'2-3/1', // Washington's Birthday, third Monday in February
'5~1/1', // Memorial Day, last Monday in May
'7/3+5', // Independence Day
'7/4', // Independence Day
'7/5+1', // Independence Day
'9-1/1', // Labor Day, first Monday in September
'10-2/1', // Columbus Day, second Monday in October
'11/10+5', // Veterans Day
'11/11', // Veterans Day
'11/12+1', // Veterans Day
'11-4/4', // Thanksgiving Day, fourth Thursday in November
'12/24+5', // Christmas Day
'12/25', // Christmas Day
'12/26+1', // Christmas Day
];
var dayOfMonth = date.getDate(),
month = date.getMonth() + 1,
monthDay = month + '/' + dayOfMonth;
if(holidays.indexOf(monthDay)>-1){
return false;
}
var monthDayDay = monthDay + '+' + dayOfWeek;
if(holidays.indexOf(monthDayDay)>-1){
return false;
}
var weekOfMonth = Math.floor((dayOfMonth - 1) / 7) + 1,
monthWeekDay = month + '-' + weekOfMonth + '/' + dayOfWeek;
if(holidays.indexOf(monthWeekDay)>-1){
return false;
}
var lastDayOfMonth = new Date(date);
lastDayOfMonth.setMonth(lastDayOfMonth.getMonth() + 1);
lastDayOfMonth.setDate(0);
var negWeekOfMonth = Math.floor((lastDayOfMonth.getDate() - dayOfMonth - 1) / 7) + 1,
monthNegWeekDay = month + '~' + negWeekOfMonth + '/' + dayOfWeek;
if(holidays.indexOf(monthNegWeekDay)>-1){
return false;
}
return true;
}
Solution 3
We have UI that defaults search inputs to last business day or a week-ago. Here's something that works both forward and backward.
// add (or subtract) business days to provided date
addBusinessDays = function (startingDate, daysToAdjust) {
var newDate = new Date(startingDate.valueOf()),
businessDaysLeft,
isWeekend,
direction;
// Timezones are scary, let's work with whole-days only
if (daysToAdjust !== parseInt(daysToAdjust, 10)) {
throw new TypeError('addBusinessDays can only adjust by whole days');
}
// short-circuit no work; make direction assignment simpler
if (daysToAdjust === 0) {
return startingDate;
}
direction = daysToAdjust > 0 ? 1 : -1;
// Move the date in the correct direction
// but only count business days toward movement
businessDaysLeft = Math.abs(daysToAdjust);
while (businessDaysLeft) {
newDate.setDate(newDate.getDate() + direction);
isWeekend = newDate.getDay() in {0: 'Sunday', 6: 'Saturday'};
if (!isWeekend) {
businessDaysLeft--;
}
}
return newDate;
};
It would be easy to pass in an optional holidays data structure and adjust for that as well.
However, generating a holidays data structure, well, that will take a little more effort and is specific not only to every country and region, but also to every organization.
Solution 4
Your main problem was that adding safety each time meant you were adding multiple days each time it looped, instead of 1. So first loop = 1, second = 1+2, etc.
I believe this works as you'd like:
var businessDays = 10; // this will come from a form
var counter = 0; // I have a counter
var safety = 0; // I have a safety variable
var ship = today = new Date(); // I have the current date and an initialized shipping variable but the buy date will come from a form
console.log(">>> today = " + today);
// now the loop...
while( ++safety <30 ){
ship.setDate(ship.getDate()+1 );
switch( ship.getDay() ){
case 0: // Sunday
case 6: // Saturday
break;
default:
counter++;
}
if( counter >= businessDays ) break;
}
// add a number of days
// the expected shipping date
console.log(">>> days = " + businessDays);
console.log(">>> ship = " + ship);
Mark Giblin
What about me? I was born, I am currently here and sucking air until I shuffle off for a dirt nap.
Updated on June 09, 2022Comments
-
Mark Giblin almost 2 years
After revisiting this script, and some modifications, the following is available to allow a user to add a feature that calculates the expected delivery date.
// array of ISO YYYY-MM-DD format dates publicHolidays = { uk:["2020-01-01","2020-04-10","2020-04-13","2020-05-08","2020-05-25", "2020-08-03","2020-08-31","2020-12-25","2020-12-28"], usa:["2020-01-01","2020-01-20","2020-02-14","2020-02-17","2020-04-10", "2020-04-12","2020-05-10","2020-05-25","2020-06-21","2020-07-03", "2020-07-04","2020-09-07","2020-10-12","2020-10-31","2020,11,11", "2020-11-26","2020-12-25"] } // check if there is a match in the array Date.prototype.isPublicHoliday = function( data ){// we check for a public holiday if(!data) return 1; return data.indexOf(this.toISOString().slice(0,10))>-1? 0:1; } // calculation of business days Date.prototype.businessDays = function( d, holidays ){ var holidays = holidays || false, t = new Date( this ); // copy date. while( d ){ // we loop while d is not zero... t.setDate( t.getDate() + 1 ); // set a date and test it switch( t.getDay() ){ // switch is used to allow easier addition of other days of the week case 0: case 6: break;// sunday & saturday default: // check if we are a public holiday or not d -= t.isPublicHoliday( holidays ); } } return t.toISOString().slice(0,10); // just the YYY-MM-DD } // dummy var, could be a form field input OrderDate = "2020-02-12"; // test with a UK holiday date var deliveryDate = new Date(OrderDate).businessDays(7, publicHolidays.usa); // expected output 2020-02-25 console.log("Order date: %s, Delivery date: %s",OrderDate,deliveryDate );
Order date: 2020-02-12, Delivery date: 2020-02-25
The prototype is written to allow inputs from forms (HTML5 forms) of date type inputs as they are already in an ISO YYYY-MM-DD format and the output is formatted as such should that be needing to update a particular field.
The typical use would be...
var delDate = new Date( ISOdate ).businessDays( addBusinessDays, holidayData );
where the delDate is an ISO format date, eg, 2020-01-01