You could use this code snippet to nicely display time so it's easier to read than one really big number of seconds, without loosing the accuracy by rounding it down to minutes or hours.

Code:

char buf[10];

int secs;

 if (secs < 100)

     sprintf (buf, "%ds", secs);

else if (secs < 100 * 60)

     sprintf (buf, "%dm%ds", secs / 60, secs % 60);

else if (secs < 48 * 3600)

     sprintf (buf, "%dh%dm", secs / 3600, (secs / 60) % 60);

else if (secs < 100 * 86400)

     sprintf (buf, "%dd%dh", secs / 86400, (secs / 3600) % 60);

else

     sprintf (buf, "%dd", secs / 86400);

Usage:

Put the code in a function like seconds_to_human(int secs, char *buf) and call it with the number of seconds you want to display and a buffer to store it in.

Extensions:

Check out the original wget code to see how they use it.  It's very clever because they use a static char[] to cache the string so it doesn't need to constantly be regenerated.

Sources:

http://www.gnu.org/software/wget/  ./src/progress.c :: static const char * eta_to_human_short (int secs, bool condensed)