Usage of FCI_DATE functions

Hi,

I am trying to write a custom Query Defintion which fetches all master agreements expiring in the current month. There are standard ones which fetch MAs expiring between a date range.. but I want to give the date range as first day of current month to last day of current month.. I came across many date functions like FCI_DATEDIFF, FCI_DATETRUNC etc but not able to figure out the usage..

For example, found this in a standard query:

<%SCHEMA%>.FCI_DATEDIFF(<%TS%>, T2.EXPIRATION_DATE_DATE, 16) ,

Here what is <%TS%> and what is the significance of number 16? Please help.

Also would be great if someone can list out all the date functions available to sourcing Query Definitions

Thanks,

Gayathri