d.t.

double time

The abbreviation d.t. stands for double time, a marching cadence of 180 steps per minute. It's twice the standard cadence of 90 steps per minute, which is known as common time.

It also stands for delirium tremens, which is Latin for “trembling delirium.” This is a nasty condition which is most often assoicated with excessive consumption of alcohol.

Obviously it would be hard to march in d.t. when suffering from d.t. This is why soldiers are not allowed to drink.