Responsive Scheduler

I'm designing a simple scheduler in which I don't need any information except days/hours, no calendar information, no titles, no description, just days/hours.

The scheduler consist in a selection of 20 minutes intervals, with the option to copy, paste and delete any selected block of hours.

The main problem I'am facing, is that the scheduler need to be responsive.

For Web it was kind of simple, because I could play with a "click and drag" gesture to select the hours in any day (I poorly sketched this, for illustration purpose):

But for mobile, the "click and drag" gesture obviously doesn't exist as that (if you scroll over the scheduler it goes to the next hours), so I tried to imagine how the user could select the hours as easy as the web. I din't want to go to the "Google's calendar" way, because touching into an interval and then selecting the hours was so much for me, so I remembered an app (I can't remember the name) that uses a weird control to drag the block hour as you want, something like this (purple block):

So when an interval is touched (on focus) the control appear and you can increase, decrease the interval of hours, when is out of focus the controller disappear.

But I have my doubts, I don't know if this is an easy and simple way, or if Am I just only overthinking it, so I want your general opinions, what do you think about this approach? Can you think of something simpler?

Thanks.