Makkah: The Sun aligned exactly over the Holy Kaaba at 2:18 p.m. on Tuesday, 28th May. It is the time when the correct direction of Qibla can be determined.
The direction of the Qibla can be determined by monitoring the shadow of a piece of wood or plastic fixed vertically on the ground. The direction of Qibla will be opposite to the direction of the shadow.
https://www.youtube.com/watch?v=79AMYGWE9MQ
Such astrological events occur on 28th May and 16th July every year. On these dates, the Sun aligns exactly over the Kabah.