Clearly, tweeting a lot during popular shows, making sure to include their hashtags is worthwhile no matter what niche you're in. It's a very good method for those wanting to gain more followers fairly quickly. It certainly beats following others in the hope that they'll follow back, which is what a lot of people do. (Actually, if you use it a lot you'll end up with consistently more people following you than the other way around, which certainly makes you look more substantial than most people using Twitter.)
The other advantage of this technique is that it can be used to get geo-targeted followings. You just have to tweet about a show made in your own nation and you'll be sure to be seen by lots of your own countrymen. You can even do it on the city level. (Local news bulletins are applicable here.)
And there is sure to be a show for you, no matter what niche you're in. If you are a food blogger, then tweeting during Master Chef would be a great idea. If you blog about building and construction there's The Block.
While you'll still get some benefit from this technique no matter what time of the day you tweet about your favourite shows, the effect is much more powerful during the time it's being broadcast. That's because everyone is sitting there, eyes glued to the TV screen, hands on their iPhones!
Make sure you do it regularly, too. You'll become a familiar face to a lot of people during these times. People will even be looking for you, thereby increasing the amount of engagement you can get.
That's why it's always a good idea to tweet consistently good stuff. If you can make your tweets funny and/or witty, that helps too, since they're more likely to be retweeted.
Crank out ten or twenty choice tweets during a show and you'll almost certainly get quite a few replies. There'll also be some trolls, of course (particularly if it's a political show). But I wouldn't recommend interacting with them while the show is on. You can always do that afterwards. The main thing is to keep referring to what's going on on screen, and to get maximum exposure from this.
Another potential benefit: Many TV shows broadcast related tweets at the bottom of the screen. It's a boon if you can score one of these because many thousands, if not millions, of people will see your Twitter handle. Just one such exposure can win you several new followers.