Invalid Time Range Should Show a More Helpful Message than "Error" on the Dashboard

[suddendust]

Selected an invalid time range:

This throws an error. Saw the logs:

java.lang.IllegalArgumentException: Invalid time range. Both start and end times have to be valid timestamps.

Would be helpful if a more helpful message can be shown to the user. Spent around five minutes figuring what the issue was.

Thanks!

[suddendust]

@jaywalker21