date.md

Javascript - Module Date

Research based on this article: https://css-tricks.com/everything-you-need-to-know-about-date-in-javascript/

format

Estructure: 'YYYY-MM-DDTHH:mm:ss:sssZ'

format: ISO 8601 Extended Format

Example: 2019-01-14T05:30:00:123

Here's the values mean:

• YYYY -> 4 digit year
• MM -> 2 digit month (where january is 01 and December is 12)
• DD -> 2 digit date (0 to 31)
• - -> Date delimiters
• T -> Indicates the start of time
• HH -> 24 digit hour (0 to 23)
• mm -> Minutes (0 to 59)
• ss -> Seconds (0 to 59)
• sss -> Milliseconds (0 to 999)
• : -> Time delimiters
• Z -> If 'Z' is present, date will be set to UTC. If 'Z' is no present. it'll be Local Time. ( This only applies if time is provided.)

######## WARNING #########

If you create a Date with a DateString without set a time, the result will be different if you live in areas behind GMT, to avoid this problem set the time 'HH' and 'mm' at a minimun.

Example: new Date('2019-06-11T00:00');

######## WARNING #########

Creating dates with arguments

You can pass in up to seven arguments to create a data/time.

• Year: 4 digit year;
• Month: Month of the year (0-11). Month is zero-indexed. Defaults to 0 omitted;
• Day: Day of the month (1-31); Defaults to 1 if omitted;
• Hour: Hour of the day (0-23). Defaults to 0 if omitted;
• Minutes: Minutes (0-59). Defaults to 0 if omitted;
• Seconds: Seconds (0-59). Defaults to - if omitted;
• Milliseconds: Milliseconds (0-999). Defaults to 0 omitted;

Examples:

// year, month, day, hours, minutes, seconds, and milliseconds.
new Date(2019, 5, 11, 5, 23, 59);

// 21st March 1988, 12am, Local Time.
new Date(1988, 2, 21);

// 25th December 2019, 8am, Local time.
new Date(2019, 11, 25, 8);

// 6th November 2023, 2:20am, Local Time.
new Date(2023, 10, 6, 2, 20);

// 11th June 2019, 5:23:59am, Local Time.
new Date(2019, 5, 11, 5, 23, 59);

Dates created with arguments are all in local time, but if you want to create a date in UTC way, you just need to use a UTC method:

Example:

new Date(Date.UTC(2019, 5, 11));

Creating dates with timestamps

A timestamp is the amount of milliseconds elapsed since 1 january 1970 (Unix epoch time).

• Tip: You only use timestamps to compare between different dates.

// 11th June 2019, 8am
new Date(1560211200000);

With no arguments

If you create a date without any arguments, you get a date set to the current time (in Local Time).

new Date();

• You can create date with new Date();
• There are four possible syntaxes:
  • With a date string;
  • With arguments;
  • With timestamp;
  • With no arguments;
• Never create a date with the date string method.
• It's best to create date eith the arguments method.
• Remember (add accept) that month is zero-indexed in JavaScript.