I tried to run the following web query to get all the uploaded dates for Bangladesh 2004 data after 2004 Jan, but all I got was Jan 2007 as a result.

http://unstats.un.org/unsd/comtradedist/refs/getDataAvailability.aspx?lowT=2004-01-01&r=50&y=2004

 Is there a way to determine when it was first published?

UN Comtrade only stores the latest data update. In your specific case, the latest Bangladesh 2004 was uploaded on January 2007.

We are working to improve revision control so that user can find out when is the first publication, full revision, etc. However, as for now, user can only find out the latest uploaded data.

 As for Bangladesh, all data from 2000-2004 were uploaded on January 2007:

http://unstats.un.org/unsd/comtradedist/refs/getDataAvailability.aspx?lowT=2004-01-01&r=50&isOri=true&y=2000,2001,2002,2003,2004,2005

note: isOri = show only original reported classification only

Thank You very much.

It would be wonderful to see when the original data set was published and when it was revised.

Now, it is possible to download data availability (containing original publised date and revision date) in XML format. See Data Availability by date of loading http://comtrade.un.org/db/mr/daYearsNewResults.aspx?nom=-1&px=ori