How to record dates for markers and polylines (sections of polylines)

I have started using uMap to manually draw travel routes on OSM, for completed past trips and planned future trips (so I have no "GPX tracks" I could upload). I would like record times+dates for each marker and polyline (or more precisely, sections of polylines). I can't see a time/date field in the properties of markers and polylines though. Does anyone know how this could be done? Can I add a "user-defined property?" If so, I would like it to be more than just a text field in which I'm recording a time/date as I would like to use the data for some reporting and analysis, e.g. how long in each country, or how many places visited in a month, etc.

Can anyone please help?

More detail/examples:

For markers, I would like to record one or more time & date or time & date ranges. For example, on a trip to Argentina I may have visited Buenos Aires twice, stayed two days the first time, and a week later stayed for further three days.

For polylines, I would like to record the "start" and "end" times. For example, a polyline drawn from Buenos Aires to Bariloche to Ushuaia and back to Buenos Aires would be along these lines: section 1: left Buenos Aires at 10am on 1 Jan, arrived in Bariloche at 3pm on 1 Jan section 2: left Bariloche at 8am on 5 Jan, arrived in Ushuaia at 2pm on 5 Jan section 3: etc. you get the idea :-)