Can we have a shared Calendar on 2 iPhones

[Magic_x_uk]

Hi. Is it possible for the following

Me and my gf would find it very useful if we could both have our Calendars on our iPhones shared with each other. So we can BOTH see what is happening with each other on each other's phone

Any way of doing this please

 

[Magic_x_uk]

My wife and I share a google calendar via our iPhones

thats what we have ended up doing. seems to work well