Isn't the problem more like: What date/location should I use in the burial field?
The date of the farewell ceremony, the actual date of the cremation or the date you set down the urn or whatever final solution you have for his/hers ashes?
Just use the information you find most important for yourself as a memory in that field and if you want other information added to his/hers timeline you have the option to manually add and name other events.
You find a [Add a New Event] button on the (Timeline) tab of every profile.
Bjørn, I understand your suggestion as work-around but it is a cumbersome approach to a fact of llfe (death) that is becoming more common - at least here in the U.S.
I suspect at some time cremation may be more common than straight burial. Possibly "burial" needs to be recategorized to something more universal.
I don't have a good alternative other than "Burial/Cremation". Possibly "Final Disposition" would work if a better category is not suggested.