convert calendar time to epoch in c programming

#include <stdio.h>
#include <time.h>

int main() {
    struct tm timeStruct;
    time_t epochTime;
    char inputDate[20]; // Assumes input in the format "YYYY-MM-DD HH:MM:SS"

    printf("Enter date and time (YYYY-MM-DD HH:MM:SS): ");
    scanf("%s", inputDate);

    // Parse input string into struct tm
    sscanf(inputDate, "%d-%d-%d %d:%d:%d",
           &timeStruct.tm_year, &timeStruct.tm_mon, &timeStruct.tm_mday,
           &timeStruct.tm_hour, &timeStruct.tm_min, &timeStruct.tm_sec);

    // Adjust struct tm members as they are zero-based or year-based
    timeStruct.tm_year -= 1900;
    timeStruct.tm_mon--;

    // Convert struct tm to epoch time
    epochTime = mktime(&timeStruct);

    printf("Epoch time: %ld\n", epochTime);

    return 0;
}