Shaney you twisted my arm....
It was in 2000. For the Millenium, the Crown Estate Office hosted two garden parties for Crown Estate tenants. One was in the Gardens at Windsor Great Park and the other was at Holyrood House DH worked for a company that was a tenant so he got an invitation for himself and companion. We all had different dangly badges (like racecourse badges) coloured according to what kind of tenant (marine, agriculture, commercial, large and small and residential) We were given tea and sarnies in a huge hot marquee, the queen was supposed to arrive around 15.30 IIRC and circulate around the marquee. It was a boiling day and Dh and I decided that we would prefer to go and look at the gardens...as londoners we had both seen the Queen and Prince Phillip and didn't expect to be able to speak to them. Anyway we we stood outside the marquee in the shade and hadn't realised that we were on the Queen's exit route. Phillip spotted Dh's marine badge and came over for a chat while the Queen worked her way down the other side. She finished first so wandered back to collect her hubby!
I must have told this before but the dress code was smart casualish as many of the invitees were not especially well off folk. The guidance specifically said wear a hat if you wish but its not a requirement. I am of "that generation" so bought a hat and matching cream gloves. I swear to you that on that day, the queen and I were the only two ladies there wearing gloves!