There are some additional time/date placeholders that you can use when creating an email template. These do not appear in the dropdown picklist when setting a placeholder so you will have to set them manually (remember to encase them in @ symbols as below).

The following placeholders can be used:

@current_date_uk@ = 19/03/2013

@current_date@ = 19/03/2013

@current_date_us@ = 03/19/2013

@current_date_uk@ = 19/03/2013

@current_date_iso@ = 2013-03-19

@current_datetime@ = 19/03/2013 15:16

@current_datetime_us@ = 03/19/2013 03:16PM

@current_datetime_uk@ = 19/03/2013 15:16

@current_time@ = 15:16

@current_time_us@ = 03:16PM