Date Format Error

Thanks again Greg_Deckler,

80% of the data is same format and lies in one of the folder so I think that helps. The columns may be slightly different in each file but I am OK with first file's column headings what it picks automatically (I know I can change that though). 

I was already using a Folder query. Looking at the automated steps applied by Power Query, I was not sure whether it expanded binaries column or other record/table colums. So, I manually expanded binaries column now and realised it takes same steps as earlier when expanded at source step below. Hope that makes sense and answer your question.

I wasnt sure but interstingly, Time intelligence was already switched off. See below.

Despite following this, the loading time had been somewhere upto 5-10 minutes. I am OK when I am closing and appying into Power BI desktop as thats one time but I got to simply look at all possible values in a column after a transformation step and it follows the same loading data process.

In other words, it goes through each file like below. Is there a way to know if folder query (binaries) helped reducing size? I am asking because the loading process goes through size of each file (so if a file is 40 mb in the folder, the below screenshot slowly moves up to 40mb and then move to next file.

Thanks very much again for your time to respond.

regards,

Gaurav