Originally Posted by Verdell

CS can call and leave a voicemail whenever they want to. But you can confidently ignore it/delete if the call came when you’re not in a contactable status. And you are never in a contactable status before midnight at the end of a CQ day. And LC after a CQ day is not subject to the 10-18 hour assignment cutout.

tl:dr On a LC day after CQ, and unless you YS something, you have no obligation to accept any report prior to 1800, and no earlier than 18 hours after proper notification (after midnight).