Hi Rahul you can force the client computer allways get the Domain controller time when a user logs in and have user polices that disable the user from changing the date and time.

>Dear Sirs/Madams
>
>Happy Cristmas, and New Year to ALL.
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>I am making a Attendance Project in which a person will Click a button and his time will automatically recorded. But I need advise If a person comes late and changes the system time and then clicks the button. What can be done for this how to avoid that please advise.
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>Thanks in Advance.
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>Early Reply expect.
>
>Rahul