Legal Question in Family Law in California

I'm not sure what chart you are talking about but I'm guessing you mean the Santa Clara Timeshare Option. First off, there is nothing in that chart that shows 7% for an "evening." The only basis for saying it does is that there are options such as "one weekend per month" versus "one weekend per month and one evening per week" that appear to add roughly 7% for the "evening." Second, unless you are in Santa Clara, the court is not obligated to use that method of calculating what percentage time the non-custodial parent has the child(ren). Even in Santa Clara, upon a showing that the actual percentages are different from the Santa Clara presumptions, or that the actual schedule does not follow any of the Santa Clara Option options, the court may follow the actual percentages. Santa Clara seems to count an "evening" really as an overnight, as it appears to credit around eight hours when an "evening" is added to a schedule. So if your evenings are not overnights, a court could quite correctly refuse to use the Santa Clara estimat. Bottom line: DissoMaster allows you to plug in an agreed or pre-determined percentage, use the Santa Clara Option, or plug in an actual hours per day schedule, day by day, for the entire year. It is up to you to advocate for what method most accurately determines percentage of custodial time. If you failed to advocate effectively for 7% per evening, and/or if the court found the actual percentages do not fit the 7% Santa Clara presumption, then you get a different percentage.

If 7% applies to one evening, then it follows that 10 evenings is 70%. That leaves 20 evenings left in an average month (but not February) that accounts for the remaining 30%? Or is that total 30 evenings 210%?

This reductio ad absurdum shows that your original premise (that one evening counts as 7%) is flawed.