2 adjectives to describe intercalations

Nor is it necessary to deny that the frequent intercalations and suspensions of his narrative, racy and suggestive as they are, and overflowing with feeling, will fret a modern reader who is always "on time," like an express-man, and is quite as regardless of what may be expressed.

And he provided for a uniform intercalation of one day in every fourth year, which accounted for the remaining quarter of a day.

2 adjectives to describe  intercalations