Full darkness?? Hmm. Have to look that up.
In June you get about 18 hours of sun (up @ ~ 4:30 and down about 11:30pm. Allow for the mountains to obstruct the sun in some places; the Chugach mountains would block it for an hour or so but you would still have a light dusk.
In July up @ 4:28 and down @ 11:38 (that is on July 1). Plan on 45 minutes less at the end of July.
June one is the pivot point as I am sure you know. We start losing daylight. Beginning of June a total of 18:44 min. End of July 17:10 minutes.
