Hi Davinian,
Thank you so much for the reply and for the tip about the other years – I didn’t know this, so you have saved me some embarrassment when the customer asks why it’s not working!!
Yes, I sorted this in the end by copying and pasting all the css from the plugin’s css sheet to my themes style.css sheet. Hope this was the right thing to do, it certainly fixed the issue. Also I found that when I put the calendar into a table and made the table width narrow, or added other cells to the left or the right of it, that also made the calendar narrower – so now I know how to get less columns when I want, which is great.
Thanks ??