main page: fix bounds error on events widget

The issue was that we were searching for events that were less than or
equal to (now + 5 days). Normally this was never an issue, but we
happened to have an event this week starting at exactly 12:00am five
days in the future, so it didn't fit in the array. A simple change of
"lte" to "lt" fixes it.

I also fixed a typo where now + 5 days was called `next_seven_days`.

cc @CJS7070 @ClareCat