Problem: Wikidata does not support calender models other than Gregorian and Julian, but there are a vast amount of data described in other calender models like Hijri, Hebrew, Bengali etc., which don't get incorporated into Wikidata.
Proposed solution: Provide a system to include other calender models so that users can input data accordingly.
Who would benefit: Non-Western communities who have data in these other calender models but have no option to include them in current system.