Change the default time of whole ionic application

I’m trying to change the default time of my whole application because when I click on < ion-datetime> its show me wrong time!

I could change the default value in one page only, but unfortunately I have so many < ion-datetime> in different pages, Its so hard to change the default value in the whole application pages.

So Is possible to change the default time of my application using location detection for example or any thing else ?