In the US Army, quick time is 120 steps per minute (30-inch steps). Double time is 180 steps per minute. One would presume that normal marching would, therefore, be 90 steps per minute, but that’s not the case. Quick time is the normal pace. There may be a slow march for special ceremonial occasions, like at Arlington Cemetery, but I’ve never seen it and I can’t find any references to it in a quick search.
There’s also at ease march, which is quick time except that the soldiers do not keep in step with one another. And there is route step, which is the same except the soldiers may talk. There is also half-step, which uses 15-inch steps.