Yonathan Mizrachi reports in +972:
The Hebrew and Muslim calendars have, at times, had an effect on the political conflict surrounding the contested Temple Mount/Haram al-Sharif in Jerusalem. Both calendars are based on a lunar cycle of 354 days, although the Hebrew calendar adds an additional month every four years, so as to match the sun cycle.
Temple Mount activists, who seek to upend the decades-long status quo and worship freely at the site, took advantage of the coinciding days to pressure the government to allow them to enter the Temple Mount. The government acceded, leading to confrontations and violence with Muslim worshippers there. Israeli politicians didn’t seem to mind.
The fact that this year Tisha B’Av coincided with the first day of the Muslim holiday of Eid al-Adha had far greater consequences. For religious Jews, Tisha B’Av marks the day Jews mourn the destruction of their Temple, and is considered one of the most religiously important days of the year — especially for those who seek to worship at the Temple Mount.