Courtesy of Harav Yaakov Markowitz

Question: how can i have my store/company open on Shabbos without any Chashash?

Answer: when we calculate ALL jewish days that are Ossur to operate business we come to 21%.

let us assume that the value of the "company" is $100,000. Take a Goy and tell him: I am giving you a loan of $21,000 and the goy takes that money and buys a 21% share in the co. so the goy owns everything of the co. on the Yomim Tovim

But the goy must pay 14% interest on the loan, so he must pay me yearly $2940. Now say i "take out" from the co. 20,000 yearly, the goy deserves 21% of that=4200-2940=1260. So you pay him $1260 yearly.

Also you can stipulate: the principal can not be repaid only after 30 years, and if the goy does not have ALL of the principal (21,000) within 30 days (after the 30 years) the the "loan with interest" automatically is revived for another 30 years etc.