Epoch time to date format conversion

Hi,

I need to convert epoch time to normal date time format.

I am using SAP BO 4.1 SP1environment.

I have one object i.e. Closed Date which has "Number" datatype in universe and giving me output like this "1439967600" in Launchpad.

In Launchpad I have change format of column by right clicking on object but it gave error as #format.

Please help asap.

Thanks in advance

Priyanka S