こんにちは、
「Today is my first day off in a long time」使えばよいです。
久々の休日です ＝ first day off after a long time. (久々 = A long time)
**2週間くらい働き続けることがよくある
I often work for 2 weeks without a day off.
ご参考になれば幸いです。
Today is the first day I've had off in a long time.
Today was my first day off in quite a while.
どちらも「今日は久しぶりの休みです。」という言い方です。
1) Today is the first day I've had off in a long time.
2) Today was my first day off in quite a while.
the first day I've had off in a long time
one's first day off in quite a while
で「久々の休み」と言えます。
もし明日が久々の休みなら、
Tomorrow will be the first day I've had off in quite some time.
と言えます。
ご参考になれば幸いです！
イギリス 
日本 
