Not sure I agree with the statement that local time is used.
Z usually refers to GMT, or UTC as our European friends decree.
06.30z in Lima isn't early morning.
Also, here's a question. If you as Captain can't see the surfaces treated, do you accept the word of the person offering you the chit/slip of paper/billet doux or do you don you outside gear and go have a look?
You = $4000 per mnth. Deicer chappy = $1000 per month?
Sir George Cayley