YOU SAID:
what is your estematied time of arrival for the party
INTO JAPANESE
パーティーの到着予定時刻はいつですか
BACK INTO ENGLISH
What time is the party expected to arrive?
INTO JAPANESE
パーティーは何時に到着すると予想されますか?
BACK INTO ENGLISH
What time is the party expected to arrive?
Come on, you can do better than that.