[Bug] filtering time intervals

**Describe the bug**
we're using a csv that features a time interval for each row. (for instance opening hours for shops)
kepler recognizes the time format (e.g., "15:00-18:00") - however the filter widget displays different information when trying to filter the time interval.

does kepler not support time intervals within a data row?
or are we supplying the data in the wrong format?

in our scenario, we want to filter shops by opening hours.

I loaded a test data set into kepler here:
[link](https://nostalgic-spence-170226.netlify.com)

Start by opening the linked Kepler demo and reproducing the time-interval filtering behavior with the referenced CSV data. Trace the filter widget's handling of values such as "15:00-18:00"; done means confirming the supported input format or documenting the precise behavior that needs correction.

Written by the indexing model from the issue text.