Export Fitbit data to Google Fit. Unlike the alternatives such as fitnessyncer.com, this offers very fine intraday granularity (every minute/second data).
Since it only stores one reading per day, and forgets the time,
it always returns 23:59:59, which looks kinda weird in Fit.
For one thing, for today it's usually in the future.
If you weigh yourself in the morning, this'll be off by most of a
day, every day, which I found irritating.
Add a config option to pick your own time-of-day, which is almost certainly closer.
Since it only stores one reading per day, and forgets the time, it always returns 23:59:59, which looks kinda weird in Fit. For one thing, for today it's usually in the future. If you weigh yourself in the morning, this'll be off by most of a day, every day, which I found irritating.
Add a config option to pick your own time-of-day, which is almost certainly closer.