Replicating Matlab XIRR function in Excel

How can I replicate Matlab XIRR in excel? I have tried the following but still couldn't get it to work.

cf=[-10,6,6,5] 
df=[datenum('1/31/2000'),datenum('6/1/2000'),datenum('12/1/2000'),datenum('6/1/2001')]
xirr(cf,df)

In Excel, I have tried to create the discount factors using 1/(1+IRR)^[(date_i-date_1)/366] for the first three cashflows where date_i is the date on ith cashflow and date_1 is date for 1st cashflow i.e. 31st Jan 2000.

I have put the discount factor for the last cashflow to be 1/(1+IRR)^[("1/1/2011"-date_1)/366+(date_4-"1/1/2011")/365].

Using the sumproduct of the discount factors and the cashflow vector [-10,6,6,5], I get the Present Value.

Using the goal seek functionality in Excel to set the Present Value as 0 by varying IRR, I get an answer of 1.033499 (with max iteration of 200 and max change of 0.00000001).

Could you let me know if I have done anything wrongly? Or provide further documentation on the formula that Matlab actually calculates the XIRR?

Thanks!