widget on the smartphone to optimally track personal goals over rhythmic time periods

The aim is to better support the user with long-term goals (smartphone widget).

For this purpose, the user should enter an interval in which he wants to track his goal (e.g. one week, starting every Monday).
The user can also enter how they would like to use their total calorie requirement during this period (e.g. - 1000 kcal).
The user also defines how long he wants to track this goal (e.g. 1 year).

The tool then calculates the total number of calories for the specified interval (= current status) from the calories that are left over each day (regardless of whether they are positive or negative).

The widget shows the current status, the target and the time remaining until the end of the interval.

As a user, I can also have a positive calorie entry on individual days, which I can balance out in my own interval. This means less pressure to stick to a fixed limit every day and gives the user more flexibility. In reality, I can simply fast for a celebration / a birthday / etc. over th