I noticed something a bit strange that I wanted to report. On the web, in Firefox 61, if I copy entries from a day where no times were logged (pre timestamp support) to today, then attempt to edit the times of the pasted entries (so that I can record an actual time to the new entries), the screen does not seem to accept the changes to the time. The mobile version (Android) lets me make the correction with no problem.
As an experiment, I copied and pasted the entries again, creating two new entries from the ones I copied. I then clicked to edit the time and, without changing the time (displayed current time in the edit fields), clicked on the description of the item. When I did this, the current time displayed in the entry.
It does not appear obvious on how to accept the changes to the time on the web version. I assumed just clicking out of the field would accept whatever changes I keyed in. This was not the case, unless I didnt change the time. Then the time displayed.
I did figure out that if I changed all three fields when editing the time (hours, minutes, AM/PM), that no change is made. If I change only one of the entries (change the hours, minutes, or AM/PM), the time is recorded. It appears that only if I change all three does it fail to record the time.
I can send screenshots if necessary.