Best time to ring FC

Hi all
Just looking for advice on the best time to call the FC.
Want to book our flights to DXB for next year and utilise PE upgrade vouchers.
I always seem to be on hold for ages with no idea of queue length
Any advice would be much appreciated
ps. I am lowly red, hubby is silver if that makes any difference ?
Just looking for advice on the best time to call the FC.
Want to book our flights to DXB for next year and utilise PE upgrade vouchers.
I always seem to be on hold for ages with no idea of queue length

Any advice would be much appreciated

ps. I am lowly red, hubby is silver if that makes any difference ?