Handle day name values better

[thomp]

The truncated form of "This Afternoon", "Th", is potentially confusing, as it suggests Thursday. Develop an approach which addresses the larger issue this represents (e.g., "Thanksgiving" also is an issue). One approach would be to rely on the start-time value (e.g., "2018-11-25T18:00:00-08:00") to identify "today". Another approach would be to check the NAME value against the set of days of the week -- if not a member of the set, then look to plan B.