It's been asked a few times, but so far, "Time" is not possible via formatdate().
hh-mm-ss are available from the [Date (Filename Friendly)] field, so you could create a new calculated data field using something like so:
mid([Date (Filename Friendly)],0,4)-mid([Date (Filename Friendly)],4,2)-mid([Date (Filename Friendly)],6,2) mid([Date (Filename Friendly)],9,2)-mid([Date (Filename Friendly)],11,2)-mid([Date (Filename Friendly)],13,2)
Will give you: yyyy-mm-dd hh-mm-ss
If you prefer, you could create two custom fields, one for the date, and one for the time, and then use them as you wish in your naming templates:
Date: mid([Date (Filename Friendly)],0,4)-mid([Date (Filename Friendly)],4,2)-mid([Date (Filename Friendly)],6,2)
Returns: yyyy-mm-dd
Time: mid([Date (Filename Friendly)],9,2)-mid([Date (Filename Friendly)],11,2)-mid([Date (Filename Friendly)],13,2)
Returns: hh-mm-ss
regards,
-marko