Ack! I was trying to be a smart guy and see how I could get it back... but I deleted it permanently too!

You will have to wait a few days to see that entry reappear: Today > Yesterday > Last 7 days > This Month. You can't recover deleted history.

Didn't think so...

I was more worried I had deleted the "7 Days" entry than the history itself (call me backwards), so I'm glad the label isn't gone for good.