Add mask options and named formats to Readme.md

Readme.md

@@ -74,6 +74,58 @@ As taken from Steven's post, modified to match the Modifications listed above:
     dateFormat(now,"N");
     // 6
 ```
+### Mask options
+
+Mask | Description
+---- | -----------
+`d` | Day of the month as digits; no leading zero for single-digit days.
+`dd` | Day of the month as digits; leading zero for single-digit days.
+`ddd` | Day of the week as a three-letter abbreviation.
+`dddd` | Day of the week as its full name.
+`m` | Month as digits; no leading zero for single-digit months.
+`mm` | Month as digits; leading zero for single-digit months.
+`mmm` | Month as a three-letter abbreviation.
+`mmmm` | Month as its full name.
+`yy` | Year as last two digits; leading zero for years less than 10.
+`yyyy` | Year represented by four digits.
+`h` | Hours; no leading zero for single-digit hours (12-hour clock).
+`hh` | Hours; leading zero for single-digit hours (12-hour clock).
+`H` | Hours; no leading zero for single-digit hours (24-hour clock).
+`HH` | Hours; leading zero for single-digit hours (24-hour clock).
+`M` | Minutes; no leading zero for single-digit minutes.
+`MM` | Minutes; leading zero for single-digit minutes.
+`N` | ISO 8601 numeric representation of the day of the week.
+`o` | GMT/UTC timezone offset, e.g. -0500 or +0230.
+`s` | Seconds; no leading zero for single-digit seconds.
+`ss` | Seconds; leading zero for single-digit seconds.
+`S` | The date's ordinal suffix (st, nd, rd, or th). Works well with `d`.
+`l` |  Milliseconds; gives 3 digits.
+`L` | Milliseconds; gives 2 digits.
+`t`	| Lowercase, single-character time marker string: a or p.
+`tt` | Lowercase, two-character time marker string: am or pm.
+`T` | Uppercase, single-character time marker string: A or P.
+`TT` | Uppercase, two-character time marker string: AM or PM.
+`W` | ISO 8601 week number of the year, e.g. 42
+`Z` | US timezone abbreviation, e.g. EST or MDT. With non-US timezones or in the
+`'...'`, `"..."` | Literal character sequence. Surrounding quotes are removed.
+`UTC:` |	Must be the first four characters of the mask. Converts the date from local time to UTC/GMT/Zulu time before applying the mask. The "UTC:" prefix is removed.
+
+### Named Formats
+
+Name | Mask | Example
+---- | ---- | -------
+`default` | `ddd mmm dd yyyy HH:MM:ss` | Sat Jun 09 2007 17:46:21
+`shortDate` | `m/d/yy` | 6/9/07
+`mediumDate` | `mmm d, yyyy` | Jun 9, 2007
+`longDate` | `mmmm d, yyyy` | June 9, 2007
+`fullDate` | `dddd, mmmm d, yyyy` | Saturday, June 9, 2007
+`shortTime` | `h:MM TT` | 5:46 PM
+`mediumTime` | `h:MM:ss TT` | 5:46:21 PM
+`longTime` | `h:MM:ss TT Z` | 5:46:21 PM EST
+`isoDate` | `yyyy-mm-dd` | 2007-06-09
+`isoTime` | `HH:MM:ss` | 17:46:21
+`isoDateTime` | `yyyy-mm-dd'T'HH:MM:ss` | 2007-06-09T17:46:21
+`isoUtcDateTime` | `UTC:yyyy-mm-dd'T'HH:MM:ss'Z'` | 2007-06-09T22:46:21Z
 ## License
 
 (c) 2007-2009 Steven Levithan [stevenlevithan.com][stevenlevithan], MIT license.