Rohan
Would you like to post your schedule of cash flows and the corresponding dates and I will have a look at it with various XIRR functions that I use
Does SAP Crystal Reports have a built-in XIRR function or does it rely on 3rd party program such as Excel to calculate IRR?
As per Excel XIRR function, it has it's own sets of problems which Microsoft has not bother to fix
In my original reply, I stated that order of dates is not important in XIRR calculation as you should get the same IRR no matter how the pair of dates and cash flows are arranged. However the underlying XNPV function will give you different net present values for different arrangements of dates and cash flows.
This is the point where Excel XIRR seem to have issues as Excel implementation of XNPV is error prone and this screws up the XIRR calculation
If you do wish to post your cash flows/dates then I can test it with my tools. If you have any programming skills given that SAP Crystal Reports permits user defined functions then you may want to implement the sample XIRR code that I have
Regards