JavaScript - Formats

There are generally 4 types of JavaScript date formats:

• ISO Dates
• Long Dates
• Short Dates
• Full Format

https://www.w3schools.com/js/js_dates.asp

Default Date Output
Independent of input format, JavaScript will (by default) output dates in full text string format.

let date1 = new Date();
document.getElementById("demo1").innerHTML = date1;

JavaScript ISO Dates
The ISO 8601 syntax (YYYY-MM-DD) is also the preferred JavaScript date format (https://en.wikipedia.org/wiki/ISO_8601). ISO 8601 is the international standard for the representation of dates and times.

The T in the date string, between the date and time, indicates UTC time: https://en.wikipedia.org/wiki/Coordinated_Universal_Time .

UTC (Universal Time Coordinated) is the same as GMT (Greenwich Mean Time).

let date2 = new Date("2017-04-30");
document.getElementById("demo2").innerHTML = date2;

let date3 = new Date("2017-04-30T12:30:00");
document.getElementById("demo3").innerHTML = date3;
    

JavaScript Short Dates
Short dates are most often written with an "MM/DD/YYYY" syntax like this:

let date4 = new Date("04/30/2017");
document.getElementById("demo4").innerHTML = date4;

JavaScript Long Dates
Long dates are most often written with a "MMM DD YYYY" syntax. Months can be written in full like January, or abbreviated like Jan.

let date5 = new Date("Mar 25 2015");
document.getElementById("demo5").innerHTML = date5;