Add best practices for working with dates

[hannarud]

Need to restructure the content of https://www.stat.berkeley.edu/~s133/dates.html in order to make it easily understandable & usable.

The most interesting cases that must be covered:

• converting from numeric Unix timestamp to clearly human readable dates and vice versa (e.g. 1484981646 should be displayed as Sat, 21 Jan 2017 06:54:06 GMT);
• converting to and from different dates formatting (e.g. 20170121 -> Jan 21, 2017 -> 2017/01/21 etc.) - the most popular cases are to be considered;
• Working with timezones (converting time from one timezone to another, making a mapping to find proper timezone for USA - as R don't understand what EST, CST, PST, MST mean)

[antoine-182]

is help still wanted ?

[hannarud]

Hi @antoine-182! Yes, if you have some ideas, I still didn't finish it. Contribution is warmly welcome!