It is never time to move on.
This is something that will be a part of their lives now.
And it’s not something that will just go away or that they will “get over.”
Losing someone will change a person’s life forever.
If you don’t understand how they’re feeling, please try to respect it. Give them the time that they need and never get annoyed with how long it takes. Because although it may lessen and seem easier to bear, it will never go away.