This unexported helper is used internally in valid_dates to optionally issue a warning for potential completeness of seed and signal data based on dates provided.
check_incomplete(seed_date, signal_date, resolution)
Operates as side-effect and returns a warning()
if there are the seed and signal dates combined indicate an incomplete week or month.
Last date available in seed object
First date available in signal object
Character vector specifying the temporal resolution (e.g., "weeks", "months")