Coerce a nullable date string into a Date, preserving "absent" (null/undefined/empty) as
undefined. An unparseable string also maps to undefined rather than an Invalid Date, so callers
never propagate a NaN-backed Date into trigger data or DB writes.
Coerce a nullable date string into a Date, preserving "absent" (null/undefined/empty) as undefined. An unparseable string also maps to undefined rather than an
Invalid Date, so callers never propagate a NaN-backed Date into trigger data or DB writes.