There may be times where the excel date is displayed as number like one below. In such case the date can be converted to string as follows

Two things

1. The J column is aligned to Left which tells there is some custom format done over the cells
2. On selecting the cell and when you check the drop down at top it shows Custom

The Column K represents the actual value of Cells in J by making it to text format. Now to convert the Column J to Text use this simple excel formula

 =TEXT(A1,"DD/MM/YYYY hh:mm:ss")