You can format a datetime column as 24 hour time in a Tablix by issuing a capital HH for the hour component in the Format property. e.g. the following expression will show 24 hour time. Note HH will do leading zeros where applicable, H will not.
dd/MMM/yyyy HH:mm:ss
… and the following expression will show regular 12 hour time with AM/PM.
dd/MMM/yyyy hh:mm:ss tt
hh->HH thats great – It takes me a while to find yout blog and solution, 🙂