Consequence : The Q++ Default Muslim Calendar is a good mathematical prediction of when the Moon's first crescents will be visible, but as these dates are ultimately determined by religious authorities, the dates so generated by Q++ may not agree, depending on the countries.
It is therefore best to either use the Q++ Saudi Calendar if you are dealing with Saudi Arabia, or countries in the Arabian Peninsula, or countries for which you have no reliable information. On the other hand, if you have some official announcement from local religious authorities, then you should create, and use, a custom Muslim calendar that will match those dates exactly.
•Re-Generate Holidays : This message is based on the analysis performed by Q++ during the most recent holidays generation, and therefore ignores any changes recently made to holidays rules and holidays sets properties. So, if you think this message is incorrect, then you may want to try to re-generate holidays using this proposed solution.