Excel problem driving me mad - new month exploding sheet

[8-P]

Hi All

I'm a relatively competent Excel user, pivots, lookups etc all no problem.

I have a large spreadsheet that I put data into every day - its sales data from the previous day, normally a few hundred rows.

Today I have downloaded my data as normal but now I have some July data it wont recognise it - works fine for every day in June but now all my pivot tables have error-ed - I cannot see what is wrong, the data looks normal.

I've checked:

source - fine
cell format for date column - Ive done a text to columns - it looks fine

Is there anything else I can check please?

I report on this daily

[Countdown]

Some of the data formatted incorrectly (eg Numbers formatted as text)?

[8-P]

Think Ive solved it to a degree. I've deleted all tabs other than the main one Im interested in - I was getting errors about pivot table 1 and 5 overlapping - they were clearly on another tab and now my main tab is ok.

So I need to track those down - always a pain and then I think itll be ok.