This command sets the time, but not the date. The seconds value is a numeric expression which specifies the number of seconds past midnight. If it includes a fraction, the fraction is rounded to match the clock hardware of the system you are using. The time can be specified to the nearest hundredth of a second.
NT Usage Notes
To set the time, you must have the "Change the system time" user right or belong to a group that has this right. Usually the Administrators and Power Users groups have this right.