It seems to me that the fully general solution to this problem would be able to specify a rate for each day of the week. Here are some use cases which would be immediately useful for me, but which are difficult to enforce properly at the moment:

- Goals for exercising on Monday, Wednesday and Friday: a certain number of minutes or reps on those days; flat on other days.

- Completing a certain number of hours (or pomodoros) of work on weekdays, but noting that I will allow myself to do less on Wednesdays when I teach a class in the evening (for which I need to allow for preparation and travel time)

- A goal to complete post-class accounting and video-editing no later than Friday.

Not quite what you want, but a possible alternative in the meantime: create a Gmail goal for "in:inbox older_than:2d" (or similar).

My 'sophisticated' implementation was along the lines of one-row-per-day, but here's a...

More sophisticated: specify date, data-value and comment columns from a particular sheet (allow multiple rows per date).

Motivation: I already track lots of stuff (e.g. pomodoros completed) in Google sheets, and having to manually transcribe data is annoying.

I gather that I might be able to do this using Zapier, but I aspire to complete more than 100 pomodoros a month so that will get expensive.

IFTTT ought to be able to do this, but it doesn't seem to be able to trigger based on changes to a sheet (or indeed any other triggers for Google Drive at all).

It might be possible to do this using Google App Script (to push data to Beeminder), but even if Ap Script will let me connect to external sites (which I am doubtful about) it would still be better to pull data rather than push it.