Standard C Date & Time
| asctime | a textual version of the time |
| clock | returns the amount of time that the program has been running |
| ctime | returns a specifically formatted version of the time |
| difftime | the difference between two times |
| gmtime | returns a pointer to the current Greenwich Mean Time |
| localtime | returns a pointer to the current time |
| mktime | returns the calendar version of a given time |
| setlocale | sets the current locale |
| strftime | returns individual elements of the date and time |
| time | returns the current calendar time of the system |