CCS/TM4C1294NCPDT: Question about using umktime() and ulocaltime()

Tool/software: Code Composer Studio

I am using a TM4C1294NCPDT CPU, CCS 6.1.2 , TIRTOS 2.16.0.08, and compiler 5.2.7.

I want to use the functions umktime() and ulocaltime() for use with the RTC and I have a link error where I can't link in the the functions umktime() and ulocaltime(). 

 undefined  first referenced              
  symbol        in file                   
 ---------  ----------------              
 ulocaltime ./SourceCode/RTC_interface.obj
 umktime    ./SourceCode/RTC_interface.obj

In the linker I am including the library(s) driverlib.lib and libc.a.  I did not find the functions umktime() and ulocaltime() in any documentation to know what library I should link in.for the functions umktime() and ulocaltime().  

I have two questions...  1 what document has the functions umktime() and ulocaltime() and 2 do I need to link in another library to build the CCS project to use the functions umktime() and ulocaltime()?

Thanks,

Doug