I was connected to a site (not Companies House) that supplies financial data of companies. The accounts' dates are such as 30 Jul 2017 and the data can be exported in CSV.
When, however, the CSV file is opened the date appears as a large number, in this case 1501372800. 30/07/2017's value in Excel is 42946, and doesn't seem to have any obvious relationship to 1501372800.
Knowing the quality of brains here, I'm wondering if any one has any idea why 30 Jul 2017 becomes such a weird number in CSV, and secondly how to convert that to a recognisable date.