What to wear to passing out parade

[Chocolou]

I've been invited to my nephews passing out parade. And I've no idea what to wear it just says bear in mind weather changes and wear comfortable shoes!!

I'm a curvy size 14 although hoping to lose a bit of weight before.

Bump

What time of year is it? Smart coat and dress if winter, smart jacket and dress if summer. And low shoes that you are happy to stand in.
Have a look at some of the footage of Kate Middleton at Prince William’s passing out parade for inspiration/ general dress code.