It did bother me there was no fall through.

Idk it works for me.

I don't think there is any possible value for the sign variable which would make that if statement do anything other than raise a TypeError.

Also "8:00:00" > "10:00:00"

but "08:00:00" < "10:00:00". comparing timestamps as strings is weird but actually works, as long as the hour is zero-padded :)

the problem with this code is that & (bitwise AND) has higher operator precedence than > and == do, so it is first trying to bitwise AND "10:00:00" with sign (which i'm assuming would also be a string) and that will always raise a TypeError.

to do what the author appears to have intended to do, they would either need use parenthesis around both comparisons to actually bitwise AND their results, or (better) to use the boolean AND operator (and) instead of &.

The boolean and operator is the right tool for the job, and since it is lower precedence it also wouldn't require that any parenthesis be added here.