My guess is he wanted to primarily store an integer for seconds into a constant.

Since one can only bless references this would have complicated to simply get a number in nummeric context. (it's still possible with an overload of "0+" )

edit

strange, his code does overloading, including "0+"

Maybe an old version of his code didn't use constant but this other technique to put a immutable literal into a package variable... like *PI = \3.14159265358979;

well who knows ... old code ... sigh