The layouts listed below provide an option in the Customize Journal Style page for you to change the way times are displayed. Some layouts provide a list of choices to select from, while others enable you to build your own time string from the system variables. A list of these variables can be found in this tutorial. For example, the time format string
%%HH%%:%%min%%
will display the time as "16:34". Here is a list of layouts in which you can change the date display format.