When are you planning to go on your summer vacation?
From when to when were you planning to go away in July?
What were the dates you were scheduled to go away on vacation?
この場合、次のような聞き方ができます。
ーWhen are you planning to go on your summer vacation?
「夏休みはいつ行く予定だっけ？」
to go on one's summer vacation で「夏休みの旅行に行く」
ーFrom when to when were you planning to go away in July?
「7月に出かけるのはいつからいつまでだっけ？」
to go away で「出かける」
ーWhat were the dates you were scheduled to go away on vacation?
「夏休みに出かける日付はいつでしたっけ？」
to go away on vacation で「休暇で出かける」
ご参考まで！
カナダ 
