"Days remaining in Sprint" in Sprint Health gadget doesn't work for 7 working days

Steps to reproduce

1. Create a new scrum board;
2. Create a new sprint;
3. Add the gadget "Days Remaining in Sprint" in your dashboard;
4. Configure it with your board and your sprint just created;
5. Save it;
6. Browse to the scrum board and under the "cog" icon (Tools) click in "Configure";
7. Browse to the "Working Days" tab;
8. Check all the 7 days of the week;
   • If you check the gadget now, it will appear a wrong random number as the number of days remaining;
9. Now uncheck any day (leaving only 6 days) checked;
   • If you check the gadget now, you will see the correct number of days remaining;

• If you keep decreasing the number of days checked everything will work just fine. This only happens with the 7 days checked.

• The "non-working days" will also generate random erroneous numbers in the gadget if the 7 days of the week are checked. If you have less than 7 days checked, the "non-working days" will be counted just fine in the gadget.

• This also seems to affect the Burndown chart (and consequently its gadget) as per the screenshot attached.