Day of the Week from a Date of Birth in C

Posted on May 8, 2012July 2, 2026 by Sandeepa Nadahalli

Problem Statement Write a C program to find the day of the week from a date of birth. For example, given 02/04/2017 (2nd April 2017), the program should tell you it was a Sunday. The Approach Pick a base year whose January 1st is a known weekday. We use 1900 (Jan 1, 1900 was a …

Difference Between Two Dates in C – mktime() and difftime()

Posted on April 2, 2012August 22, 2026 by Sandeepa Nadahalli

Computing the difference between two dates in C is a classic exercise that most tutorials get subtly wrong — hand-rolled day counting that forgets the century leap-year rules, so 1900 counts as a leap year when it wasn’t. The C standard library already solved this: convert each date to a time_t with mktime(), subtract with …