Question

I’m a beginner in C.

• Is there any datatype for dates?
• In C we have for working with time, is there one for dates too?
• How can I calculate difference between two dates?

Answer 1

Is there any datatype for dates?

No, inbuilt datatype in C , you have to defined user-defined data type.

How can I calculate difference between two dates?

You may try this:

struct dt
{
  int dd;
  int mm;
  int yy;
};
typedef dt date;  

In main() you need to declare three variables for type data.
In following example today difference,
for example you wants to take difference between current date (c_date) and date of birth (dob)

  date dob,c_date,today;

  if(c_date.dd>=dob.dd)
    today.dd = c_date.dd-dob.dd;
  else
  {
      c_date.dd+=30;
      c_date.mm-=1;
      today.dd = c_date.dd-dob.dd;
   }
   if(c_date.mm>=dob.mm)
     today.mm = c_date.mm-dob.mm;
   else
   {
      c_date.mm+=12;
      c_date.yy-=1;
      today.mm = c_date.dd-dob.mm;
   }
   today.yy = c_date.yy-dob.yy;

In today you have difference between two dates.

There is one more way: double difftime (time_t end, time_t beginning);
Read this answers:
1. How to compare two time stamp in format “Month Date hh:mm:ss”
2. How do you find the difference between two dates in hours, in C?