these days是一般现在时吗？

是的。these days是“现在, 目前”的意思。

I am busy these days.
我这些日子很忙。

Business is looking up these days.
生意近来正在好转。

How are you doing these days?
这些日子你怎么样？

It has been raining these days.
这几天一直都在下雨。