Wedding itinerary cards are timeline cards that couples can use on their Big Day.
The bride and groom can hand them out to vendors, the bridal party, and family. The couple could include them with the programs, or in hotel "welcome" baskets. The size needed will depend a lot on how many times/sections that the couple needs to include, and also on how much of a design the couple would like to add in there.
4x3 inches & 4x2.5 inches
The following itinerary timeline is an extra long at 8.5x3 inches; Enough room to include multiple days.
You should think about: 1) The times and events you would like to include.
2) Size of the card (the more events, the longer the card will need to be).
3) What images and colors you would like on the card.
4) Whether you would like me to create a custom image/graphic to depict one or more of your events, something not shown on any of these examples.