Usage of “back half” [closed]

The following article from CNBC.com states:

Fauci says Covid could be under control in ‘back half of 2021’ if enough people are vaccinated.

I assume that by “back half” Mr. Fauci means “second half”, but I wonder if this is a common usage, possibly an AmE one, or just a figurative, one-off, usage.

It may be understood as an analogy with a train, for example. The back of the train is the part that arrives last in a station. The part of the year that arrives last is the later months leading up to December. Hence back half of the year is the period roughly from July to December.

• It's not a one-off. 'back half' is a metaphorical way of saying 'second half'. Using 'back' instead of 'second' (of two parts) appears in other instances like the relatively common 'back nine' for holes 10 through 18 in golf.
• It is rarer than 'second half' (but note that many of those instances of 'back half' are spurious cross-sentences collocations).
• It seems to be just as common in both American and British English writing