Change page password every day (predictable password ;) )

It need not be very complicated. You can simply create a pattern like 2018-09-07-ABC (suffix of ABC) for the date 2018-09-07.

Set up the password creation/validation logic like password = md5('2018-09-07-ABC').

An administrator if they know the pattern, they can anytime goto any online md5 utility such as http://www.md5.cz and enter the pattern for current date.

Say for example today is December 25, 2018. Then they will enter 2018-12-25-ABC and the hash will be b21746c6db1c5323f28dd874fe60165f

TIP: You do not need to use entire 32 character password. Using first 8 characters (or any desired length) would be easier.

Sample PHP Code the generate password of length 8:

$md5hash  = md5(date('Ymd') . '-ABC');
$password = substr($md5hash, 0, 8);

Note: Take care of the timezone being used at the server when generating the password.