code for trial versions of arbitrage finding software

I require some code written to make my current arbitrage software work as a trial version. I need four different trial expiry times which are , 30 days,90 days, 180 days and 365 days. This will work as follows- the code will be written to allow the software to open without a password and work for between 30 - 365 days [ 4 versions] then AFTER the time has expired a password prompt box will appear if the user attempts to open the software after the expiry date.I will supply the password. This will have to defeat simple changing of the computer clock/date, so will involve some code written to monitor each time the software is started and record this to ensure the software cannot be cracked simply. i have the source code and can supply the password for the code. any questions please ask.