Currently I store the time in my database like so: 2010-05-17 19:13:37
However, I need to compare two times, and I feel it would be easier to do if it were a unix timestamp such as 1274119041. (These two times are different)
So how could I convert the timestamp to unix timestamp? Is there a simple php function for it?
Getting a unixtimestamp:
$unixTimestamp = time();
Converting to mysql datetime format:
$mysqlTimestamp = date("Y-m-d H:i:s", $unixTimestamp);
Getting some mysql timestamp:
$mysqlTimestamp = '2013-01-10 12:13:37';
Converting it to a unixtimestamp:
$unixTimestamp = strtotime('2010-05-17 19:13:37');
...comparing it with one or a range of times, to see if the user entered a realistic time:
if($unixTimestamp > strtotime("1999-12-15") && $unixTimestamp < strtotime("2025-12-15"))
{...}
Unix timestamps are safer too. You can do the following to check if a url passed variable is valid, before checking (for example) the previous range check:
if(ctype_digit($_GET["UpdateTimestamp"]))
{...}
If you're using MySQL as your database, it can return date fields as unix timestamps with UNIX_TIMESTAMP:
SELECT UNIX_TIMESTAMP(my_datetime_field)
You can also do it on the PHP side with strtotime:
strtotime('2010-05-17 19:13:37');
if you store the time in the database, why don't you let the database also give you the unix timestamp of it? see UNIX_TIMESTAMP(date), eg.
SELECT UNIX_TIMESTAMP(date) ...;
databases can also do date and time comparisons and arithmetic.
