Add counter-variable "experiment day"

For better human navigation through the data, another co-indexing variable "shot day" or "experiment day" should be added. An automatic increment upon realtime is to be discussed. The workflow is, that a campaign has a time frame of several day, typically some weeks. During that period, on specific days shots will be taken. These are of course identified by the timestamp. But that variable is quite a cluster of information. A redundant counter, counting the shot days, is desired by experimenters. This counter should increment whenever a shot counter is set to 1 (or set lower than the previous shot counter). Experimenters are a bit confused when restoring the app for a new shot day and the next counter is not 1. A convenience button could be added "new shot day", incrementing that counter, setting the shot counter to 1 and emptying all fields.