Happy Birthday Kamran

Here on Quran (page 77), it is hand-written in Urdu (with blue pen) that "Kamran was born on Friday 21st July 1977". Birth dates of my all brothers and sisters (we are 8) were recorded on Quran immediately after our birth.
However, there is a conflict about my birthday. The calendar of year 1977 shows that on 21st July it was Thursday and not Friday (as written above).
http://www.flicklives.com/Timeline/1977_cal.html
That means I was born either on 21st or on 22nd, although my mother insists on 21st July Friday.
Some of my birthday images are here
http://wwwisg.cs.uni-magdeburg.de/~kamran/birthday/birthday.html