“March ahead’ usually means “move forward.” “March” means walk, but it is the kind of walking that army soldier do (meaning, a large group of people walking together). Here, the sentence appears to refer to Daylight Savings Time, which begins on March 10 in most parts of the United States (and maybe other countries, but I don’t know). On that date, everyone moves their clocks forward by one hour. By doing that, the sun appears to rise and to set one hour later — which makes it seem like the daylight hours are longer, since you get more daylight at the end of the day when you are awake to enjoy it. Moving the clock ahead by one hour is kind of like making time “march ahead” or “move forward.”

In the US we also use the phrases “spring forward” and “fall back” to remind us which way to turn the clocks depending on the season.

As John says, marching is many people stepping at the same time. All their legs move as one. The connection is that all the clocks move at the same time, er, about simultaneously. . It is also obviously a pun with the date, being March for the USA according to John. Other parts of the world use other dates. And of course, if in the southern hemisphere will tend to adjust the oppostite direction. . John has a small typo ...kind of walking that army soldiers do ...