Duration of a month in seconds? Before you balk at the idea, there exists a definition of a constant month duration for accounting stuff. I you hate dates - and yourself - try accounting, there's mind boggling stuff that makes the engineer mind recoil in absolute terror.

The expression on the left hand side advances time (as a domain object) by exactly a month, then converts the result to integer unix time. The expression on the right adds 2629746¹ to the current unix time.

The conversion becomes dangerously magical in the presence of shared code that accepts both object and integer representations of time & duration. A consumer from one part of a system can inadvertently obtain different results to another unless they use identical calling conventions.

[1] this is 1/12 of the mean length of a gregorian year²

[2] 365.2425 days i.e. 31,556,952 seconds