I’ve been studying sunrise and sunset, moon rise and moon set, and moon phases charts for December 1814 and January and February 1815. My characters in my latest work in progress live in a quiet corner of the country within an hour’s carriage ride of Bath, and want to attend the assemblies there. Dreadful roads and poor lighting are an accident waiting to happen, which the Georgians knew even better than we do, living in a world where street lighting hadn’t spread beyond the wealthier parts of the bigger towns.
If you lived in a large country house and wanted to hold a party, you’d probably arrange it for a time when the moon would give your local guests sufficient light to see their way, perhaps with a bit of assistance from a pair of carriage lamps (fueled by oil). According to some research done by the US army, your driver would be able to pick out sufficient detail for safe driving at a distance of 400 metres on a cloudless night under a full moon that is high enough in the sky to light the road you’re using. This could drop as low as 20 metres at the quarter moon, making for a very slow trip.
In town, those out for the evening would send footmen or hired link boys to go ahead of the carriage with links (bundles of rush dipped in pitch and set alight to make a torch) or oil lamps. I guess close neighbours might have done that in the country, too. But not my characters — they have too far to go, so are stuck with partying only on a fine and moonlit night.