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PHP adalah bahasa pemrograman yang umum dipakai dalam pembuatan dan pengembangan suatu web. Sebetulnya, dilansir dari PHP.net, PHP merupakan singkatan dari PHP: Hypertext Prepocessor. Menurut situs tersebut, PHP adalah bahasa pemrograman yang banyak digunakan secara luas dan secara khusus sesuai untuk pengembangan web.
Versi terbaru dan stabil dari bahasa pemograman PHP saat ini adalah versi 8.0.
PHP adalah singkatan rekursif untuk "PHP: Hypertext Preprocessor", yaitu bahasa pemrograman yang digunakan secara luas untuk penanganan pembuatan dan pengembangan sebuah situs web dan bisa digunakan bersamaan dengan HTML. PHP adalah bagian dari bahasa skrip, seperti JavaScript dan Phyton.
I have marked this as a community wiki so feel free to edit at your leisure.
"The year 2038 problem (also known as Unix Millennium Bug, Y2K38 by analogy to the Y2K problem) may cause some computer software to fail before or in the year 2038. The problem affects all software and systems that store system time as a signed 32-bit integer, and interpret this number as the number of seconds since 00:00:00 UTC on January 1, 1970."
Times beyond 03:14:07 UTC on Tuesday, 19 January 2038 will 'wrap around' and be stored internally as a negative number, which these systems will interpret as a time in December 13, 1901 rather than in 2038. This is due to the fact that the number of seconds since the UNIX epoch (January 1 1970 00:00:00 GMT) will have exceeded a computer's maximum value for a 32-bit signed integer.
DATE column type. If you need higher accuracy, use DATETIME rather than TIMESTAMP. Beware that DATETIME columns do not store information about the timezone, so your application will have to know which timezone was used.Try wherever possible to use large types for storing dates in databases: 64-bits is sufficient - a long long type in GNU C and POSIX/SuS, or sprintf('%u'...) in PHP or the BCmath extension.
So a MySQL DATETIME has a range of 1000-9999, but TIMESTAMP only has a range of 1970-2038. If your system stores birthdates, future forward dates (e.g. 30 year mortgages), or similar, you're already going to run into this bug. Again, don't use TIMESTAMP if this is going to be a problem.
Few PHP applications will still be around in 2038, though it's hard to foresee as the web hardly a legacy platform yet.
Here is a process for altering a database table column to convert TIMESTAMP to DATETIME. It starts with creating a temporary column:
# rename the old TIMESTAMP field
ALTER TABLE `myTable` CHANGE `myTimestamp` `temp_myTimestamp` int(11) NOT NULL;
# create a new DATETIME column of the same name as your old column
ALTER TABLE `myTable` ADD `myTimestamp` DATETIME NOT NULL;
# update all rows by populating your new DATETIME field
UPDATE `myTable` SET `myTimestamp` = FROM_UNIXTIME(temp_myTimestamp);
# remove the temporary column
ALTER TABLE `myTable` DROP `temp_myTimestamp`
Resources
When using UNIX Timestamps to store dates, you are actually using a 32 bits integers, that keeps count of the number of seconds since 1970-01-01 ; see Unix Time
That 32 bits number will overflow in 2038. That's the 2038 problem.
To solve that problem, you must not use a 32 bits UNIX timestamp to store your dates -- which means, when using MySQL, you should not use TIMESTAMP, but DATETIME (see 10.3.1. The DATETIME, DATE, and TIMESTAMP Types) :
The
DATETIMEtype is used when you need values that contain both date and time information. The supported range is'1000-01-01 00:00:00'to'9999-12-31 23:59:59'.The
TIMESTAMPdata type has a range of'1970-01-01 00:00:01'UTC to'2038-01-19 03:14:07'UTC.
The (probably) best thing you can do to your application to avoid/fix that problem is to not use TIMESTAMP, but DATETIME for the columns that have to contain dates that are not between 1970 and 2038.
One small note, though : there is a very high probably (statistically speaking) that your application will have been re-written quite a couple of times before 2038 ^^ So maybe, if you don't have to deal with dates in the future, you won't have to take care of that problem with the current version of your application...
A quick search on Google will do the trick: Year 2038 problem
http://en.wikipedia.org/wiki/Year_2038_problem has most of the details
In summary:
1) + 2) The problem is that many systems store date info as a 32-bit signed int equal to the number of seconds since 1/1/1970. The latest date that can be stored like this is 03:14:07 UTC on Tuesday, 19 January 2038. When this happens the int will "wrap around" and be stored as a negative number which will be interpreted as a date in 1901. What exactly will happen then, varies from system to system but suffice to say it probably won't be good for any of them!
For systems that only store dates in the past, then I guess you don't need to worry for a while! The main problem is with systems that work with dates in the future. If your system needs to work with dates 28 years in the future then you should start worrying now!
3) Use one of the alternative date formats available or move to a 64-bit system and use 64-bit ints. Or for databases use an alternative time stamp format (eg for MySQL use DATETIME)
4) See 3!
5) See 4!!! ;)
Bros, if you need to use PHP to display timestamps, this is the BEST PHP solution without changing from UNIX_TIMESTAMP format.
Use a custom_date() function. Inside it, use the DateTime. Here's the DateTime solution.
As long as you have UNSIGNED BIGINT(8) as your timestamps in database. As long as you have PHP 5.2.0 ++
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