Libfaketime

libfaketime command specific date and time faking

For example you want to test how certain function will behave at certain time. You can isolate that function in a seperate script, and then launch it via command line. To install libfaketime package execute yum install libfaketime.

And an example to simulate some date would be faketime '20xx-0x-xx 00:00:00' php date.php. Now instead of default php time, you will simulate the date you entered. (x represents any number).