Timestamp generator

Value converters

Generates timestamps from strings, displays info about dates and formats them in a neat way.

All fields are set to current time by default so feel free to roll the dice right away and see what this tool has to offer. 

Generate
Time string («12 Dec 2012») or timestamp:	Generate: H:M:S D/M/Y Ctrl+Shift+E
Use this strptime() format to parse the time string:	Ctrl+Shift+E
Relative time string: This is relative to the above. Allowed operators are: ¶ + – / * ( ) – arithmetics and grouping; . , – fractions («1.5» or «1,5» – the same); spaces inside expression are allowed but ignored. Also, shortcuts exist for (m)inute, (h)our, (d)ay and (w)eek. ¶ Examples: ¶ «+1d» (tomorrow), «-1d – 1/2m» (yesterday, the same hour but half a minute ago).	Ctrl+Shift+E
Make all times relative to this timezone (UTC is GMT+0 – see others):	Ctrl+Shift+E
Format string for DateFmt (leave empty to hide):	English Русский Ctrl+Shift+E
If necessary, setlocale() for date and strftime calls:	Ctrl+Shift+E
Format string for date():	Ctrl+Shift+E
Format string for strftime():	Ctrl+Shift+E
View:	Tabular Textual (one line per item). Textual (comma-separated items on one line). JSON (JavaScript Object Notation). XML (eXtensible Markup Language).

UNIX timestamp (or Unix time) is a number of seconds passed since 1^st January 1970. As name states timestamps are mostly used in *nix systems (including Linux and FreeBSD) to represent exact date & time values. For example, number 1303578469 stands for 17:07:49, 23^rd April 2011 (try it yourself).
Timestamp doesn't represent leap seconds and thus it's not a proper UTC. 

Technically timestamp is (usually) a signed 32-bit integer and as a consequence it's incapable of representing dates after 03:14:08 UTC on 19 January 2038 – so-called Year 2038 problem. When the value overflows the time for Unix systems using traditional signed time_t type will jump back by 68 years. 

That said, Microsoft DOS had a valid time range from 1980 untill 2099 years. 

There are other formats used to represent time. For example, Windows systems use 16-byte records to represent file times which have a wider range of years (1601 through 30827) than Unix time does (1970 through 2038 excluding negative timestamps) and is also capable of representing milliseconds. 

DateFmt 

This is a standalone PHP class – all-in-one solution for formatting date and time. It focuses on native standards and easy to read and remember format string. It also adds (by means of format string) a number of functions that do not exist in standard routines – such as relative time («3 weeks ago»). 

Full reference, as well as download section, can be found at the project's homepage here. Here most commonly used format strings are listed. 

Format strings 

Numeric format strings often have either one or two hash symbols (#) following them. One hash symbol tells that it's indeed a format string while two hash symbols also pad it with a zero if it's smaller than 10.
For year (y##) this is an exception as two hash symbols stand for 4-digit year year instead of 2-digit (y#). 

Similar idea goes for word format strings that have either one or two underscores (_) following: one underscore is required for a format string while two make it output full name instead of short (e.g. «January» instead of «Jan»). 

Example DateFmt call (see the reference): 

echo DateFmt::Format('D__, d##my');    // => Tuesday, 26/04/2011

Full reference to DateFmt format string is located here. 

date() 

Standard PHP function date() supports a large variety of format strings and it's fast and convenient to use – for example, to check if two dates are about the same day the following code can be used: 

date('dmy', $date1) == date('dmy', $date2)

However, when using it to format more or less complicated string there are at least 3 problems: 

1. Poor to none localization – by default format strings that output a word (such as «M» for month – «January», etc.) return it in English; this can be fixed by changing current locale but it doesn't always work.
2. The way standard format strings are (i.e. just letters in contrast with strftime, see below) prevent from putting into format string any other «human» words because they will be mistaken for format strings unless prefixed with a backslash.
3. Format strings are hard to remember – usual formats for day or month number («d» and «m») are fine but for less used they seem to be random (for example, «z» for day of year).

Format strings 

Since date is a standard PHP function it doesn't need any external libraries and is used like this: 

echo date('d.m.y H:i');   // => 26.04.11 14:52

Format strings passed as date()'s first argument are listed below. 

strftime 

There's another PHP function used to format date & time – strftime. It's used less often that the date function. It differs from it in the way format string is interpreted: control characters (e.g. «d» for day) are prefixed with a percent sign (%) to avoid collisions with normal word characters (which is a common problem for date). This is where its name comes from – standard printf() function also formats strings in this way. 

strftime() has the same format strings as date() with a few exceptions. 

An example of how this function is used: 

echo strftime("%d.%m.%y %H:%M"),"\n";   // => 26.04.11 15:21

You can find the list of strftime()'s format strings in the PHP manual.