tcsh: make 2-digit hours in prompt

I am attempting to simply get a standard lexigraphical time display in the prompt and the history file in the range of 00:00:00 to 23:59:59. I've tried

`set prompt=%P$ `

but this just produces, for example,

`7:12:43$ `

when time is before noon. I need it to display 07:12:43 instead so that the times sort correctly and the widths are uniform. Can I do this?