I totally agree with this sentiment, but you do have two ways that people want to interact with the data. Scrub by day, scrub by hour, depending on what level of detail is wanted. You might need still two controls, but they should at least be the same type of controls.
Alternatively, you could add a drop down to select the granularity and then use a single slider control.
Edit: This is based on just seeing the reddit one, BTW. I tried to check out yours, but it seems that it's popularity has flooded the server.