I was away for almost two weeks a couple of months ago. My sister was nice enough to come by twice a day to check on my Amazon. She gave him fresh food and water every day and once he was used to her (and lonely enough to want to behave to get some human interaction) she would let him out for a few hours each day. She also left the radio on for a couple of hours a day between her morning visit and afternoon/evening visit. I knew it was very likely that he might not be ok with her handling him so I got him used to staying in the cage some nights when I was home so he didn't assume he had to be let out just because I was home and he wanted out.
If you let your parrots out every day for the entire time you're home start leaving them in their cages more, sometimes for the entire day. You want to get them used not always being out in case whoever is looking after them is either uncomfortable letting them out or unable to handle them. You want to make sure that the new temporary routine won't be a complete shock to them. There's no faster way to lose a bird sitter than having a bird that screams non-stop because they think they have to be out of the cage just because somebody is in the house with them

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Especially if you're leaving your bird with a 'non-bird' person it's a good idea to leave them with a manual like Michael said. Some people might do something innocently and not know it's harmful to your birds. Especially if you're leaving them at somebody else's house. Make sure they don't cook with Teflon pans, let them know the dangers of open water (i.e. toilets), open windows, open doors, drafts, chemicals, etc.