Refers to this time or around now; used to mean 'around this time' or 'at the present moment'.
今頃、彼はもう会場に着いているだろう。
By now he should already have arrived at the venue.
今頃になってそんなことを言われても困るよ。
It's troublesome to be told that at this late stage.
今頃は仕事が忙しくて、週末にしか休めない。
These days work is busy and I can only rest on weekends.