Date Functions

[ShootingStar]

Could someone please explain the reason why the date functions in php, in particular date(), revolve around unix timestamps which are only useful for dates between 1970 and 2038. This seems a somewhat archaic system that is impractical for many solutions e.g. family mappings and trees where dates can go back centuries (my own family history dates back to the 12th century!)
Can anyone tell me if there are any functions or libraries available for some date functions that are not dependant in unix timestamps? I would like a function to format a date based on the input of three parameters:
(date, format1, format2)
where date is the date to be formatted, format 1 is the format of the supplied date and format2 is the format required.
Ok so simple date formats like dd/mm/yyyy are simple to code myself but I would like a reliable function that can handle the full array of date formats including long day and month names etc.

[devinemke]

Originally posted by ShootingStar
Could someone please explain the reason why the date functions in php, in particular date(), revolve around unix timestamps which are only useful for dates between 1970 and 2038.

not true. if your OS supports it, timestamps can be negative intergers, which can represent pre-1970 dates.

[ShootingStar]

True but... quote from php.net manual:

The valid range of a timestamp is typically from Fri, 13 Dec 1901 20:45:54 GMT to Tue, 19 Jan 2038 03:14:07 GMT. (These are the dates that correspond to the minimum and maximum values for a 32-bit signed integer). On Windows this range is limited from 01-01-1970 to 19-01-2038.

What about pre 1901?

[devinemke]

timestamps are nothing more than numbers, they integers that represent a specifc point in time. since numbers are infinite, as are the range of dates that timestamps can theoretically represent. the problem here is not with the timetsamp system itself, it is with how big of a number your OS can deal with. if you use a 32bit OS then there is a finite sized integer that your system can handle and thusly a finite range if dates that be represented via timestamps. if you use a 64bit OS, 128bit, etc.. then there are a greater range of dates that you can use (but still finite).

the bigger picture here is that different systems have different proprietary ways of storing temporal data. let's say we have two date/times from two different computer systems:

1. April 18th, 2005 at 12:12pm EDT
2. 2005-04-01 22:14:26

these two dates are just strings and would have to be broken down into pieces to be effectlivey compared/added/subtracted. this gets cery complicated when dealing with lots of different (and incompatible) date formats. this is where timestamps come in. again, timestamps are just numbers. numbers are very easy for computers (any computer ever made) to campare/add/subtract and thus they make an ideal way to represent dates/times.

make sense?

[ShootingStar]

I don't disagree with you. But my problem is:- is there a function that doesn't need to use timestamps.
I don't really think its time yet to go spending lots of money on a 64bit system just so I can format some dates in my OpenSource (FREE!) PHP/Apache environment!

[Ravenous]

Timestamps of any sort are impractical for family trees, anyway. Do you need resolution the second or just the date?