Is there a way to maintain a "balance" of unused calories (or carbs, etc.) that I can then use another day of the same week?
I don't know of any way to do exactly what you're asking, but if you're gold, you can go to Trends -> Nutrition Reports, and set a custom range of days for which you will see the average daily deficit. It would be nice if cronometer could do nutritional reports for different amounts of time than a day. When you select more than one day it will just generate a daily report that is the avg. of the days you selected, so you will have to do some math.
For your use case I suggest:
At the beginning of each week go to trends -> nutrition reports and set the custom date range to Monday - Sunday or Sunday-Saturday, change All Days to non-empty days so it doesn't average the days that are yet to come.
Cronometer will display the daily average deficit or surplus of calories. Multiply this by the number of days in the week that have passed to get your total deficit or surplus for the week.
For example, let's say I'm about to go to bed on Friday and I check my nutrition report and it says that I have a daily average deficit of 100 kcals. I multiply by the 5 days that are being averaged to get my total deficit for the week, which is 500kcals under my goal that I can make up for on saturday and sunday.
Hope that's helpful.
Here is a feature request that is relevant to your question:https://forums.cronometer.com/discussion/3274/show-total-calories-deficit-for-time-period
Thank you. That all makes sense, and I configured as you specified.
Feature request for Cronometer: Please create a report that provides the info described in paragraph #4 above. Or alternatively, in the daily diary, show a "week to date calorie deficit" o'meter ...
For those of you that question the rationale for this request … I would like to maintain the “weight loss” track, but allow the ability to save up some calories on weekdays, so I can splurge a bit on a Fri/Sat. This is similar to WW “weekly points” or “carry-over points” etc.