(170323) — KARACHI, March 23, 2017 (Xinhua) — Pakistani JF-17 Thunder jets perform during celebrations to mark Pakistan Day in southern Pakistani port city of Karachi, on March 23, 2017. Pakistan Day, or Republic Day, is a national holiday in Pakistan to commemorate March 23, 1940 when a resolution was passed in Lahore, now Pakistan’s eastern city, to demand a separate homeland for the Muslims of the British Indian Empire. (Xinhua/Arshad) (zw) RSS.