So if you ask what I've been doing the past ten days...
"この10日間何していたかという"
- So if you ask what I've been doing the past ten days...
- I'm going to catch you op on what I have been doing the past ten days.
- It's been a while since my last journal entry. Here's a short recap of the past ten days.
In case that you're wondering what I've been up to these past 10 days...
ご質問ありがとうございます。
日記で「この[10日間](https://eikaiwa.dmm.com/uknow/questions/43294/)何していたかという」から始まりたいなら、英語で「In case that you're wondering what I've been up to these past 10 days...」と言えます。
ご参考になれば幸いです。