Implementing this would require fairly major overhaul of the existing program data structure so it isn’t feasible at the moment. However, you can leverage multiple programs to achieve what you want. Here is the idea:
– Days watered in both weeks: put these in a normal Weekly program.
– Days watered in only one of the two weeks: for each one, create an Interval program, set the interval to 14 days, and set its first run to that day. It will then repeat every 14 days (exactly 2 weeks) on the same weekday.
I understand this is more tedious and less convenient than a single 14-day program type. On the other hand, you can ask an LLM (e.g. Codex, Claude Code) to create these programs for you. Basically, describe how exactly you want the program to run, and ask it to split it into multiple programs and create each.