Ken「飲み会来る?」Taro「喜んで(行くよ)。」Ken「じゃー、6時20分集合で」=K:Would you like to come a little get-together? T:Sure,I'd love to. K:We'll meet at twenty past six there、OK? T:Gotcha.で可?
We'll meet at twenty past six there、OK? は、少し不自然な表現に聞こえます。
”We will meet there at 6:20pm, Is that OK?” や、”Let's meet there at 6:20pm!”というほうが良いと思いますよ。ご参考になさってくださいね。