Better support for date-time

[ILAsoft]

Is your feature request related to a problem? Please describe.
It is very hard to work with date-time fields (eg "query" on them). The interface already supports unix datetime as a number, but a better support for it would be appreciated. EG. I can scan for event_times > "number" 1564072758970 right now, but I have to figure out said number. Note, this is not about the string (eg 2019-07-25T20:17:45.046226) based values as those I believe are much tougher to work w/in Dynamo as it is. Similarly not covering Date and Calendar types (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/DynamoDBMapper.DataTypes.html) as they don't seem to be as prevalent at this time/yet.

Describe the solution you'd like
It would be nice to be able to select it via a date-time picker (and better yet, to also have some common choices in addition to it, eg last 15 minutes and the like).

Describe alternatives you've considered
Currently using number based approach, eg. scan for event_times > "number" 1564072758970

Additional context
Add any other context or screenshots about the feature request here.