In light of https://bugzilla.mozilla.org/show_bug.cgi?id=1865080, this ballot ensures that all readers of the BRs understand that time periods measured in days (such as validation document reuse periods, random value usage periods, and revocation timelines) are measured precisely, not in calendar days.

Notes:
- This ballot bears some similarity to Ballot SC-52, which never came to a vote.
- This ballot does not strictly define a "month", allowing infrequent tasks to continue to be executed on the same numeric day of each month, regardless of the number of days in that month.

Add a sentence modeled after Clint's statement that relying parties
interpret periods of time to be their minimum value.

Scope the existing high-precision sentence to just validity periods and
validity intervals.