Says how long ago something was answered, in the coarsest true unit.
A replay states its age because mise refuses to decide staleness on the
operator's behalf: an accession names a study that will not change, an
MRN can gain one tomorrow, and no heuristic tells those apart reliably.
Parameters
at: string
An ISO timestamp.
Returns string|null
A phrase like 3 months ago, or null when the stamp is unusable.
Says how long ago something was answered, in the coarsest true unit.
A replay states its age because mise refuses to decide staleness on the operator's behalf: an accession names a study that will not change, an MRN can gain one tomorrow, and no heuristic tells those apart reliably.