Hi,
Your question is not explicit but i will try to give you something.
use strftime(X, Y) :
This function takes an epochtime value, X, as the first argument and renders it as a string using the format
specified by Y for example :
... | eval n=strftime(_time, "%H:%M") here n content the values of the field _time but in term of hours and minutes only.
Use ctime(X)
This function Convert an epoch time to an ascii human readable time. Use timeformat option to specify exact format to convert to.
Example ... | convert timeformat="%H:%M:%S" ctime(_time) as timestr
So i think you can replace _time by your field that content your dates and for more types of time format you can take a look in
http://docs.splunk.com/Documentation/Splunk/6.2.2/SearchReference
in the section Common date and time format variables
for convert filename date to epoch time format try something like this
.....| convert timeformat="%m/%d/%Y:%H:%M:%S" ctime(date) as date
look more detail in search reference manuel
Hmm could pls provide more details/example?