Jump to next day with activity in the archive view
Start at https://gitter.im/gitterHQ/gitter/archives/2019/02/14 for clear example.
The "previous day" and "next day" meaning <
and >
(at the right, with the heatmap calendar) should take the viewer to the next-non-empty date, not to the absolute next date.
On low-traffic or burst-traffic channels, it makes a big difference to the catch-up-reading process.
Discussed in gitter, March 11, 2019 4:27 PM