In a word, "NO."
When someone says, "That was in the past" or "you should be over it by now" or similar, what they're basically telling you is, "I don't want to put forth the emotional effort or ding to my pride/sense of righteousness to do the work required for you to forgive me." or if they are telling you to forgive someone else for "past" deeds, they're saying, "Your feelings are uncomfortable and inconvenient for me, so stop having them."
And I'm sorry, no. If someone wants the reward of forgiveness, peace, family harmony, they have to put in the work required to achieve it.
I have a family member who not only plays the "that is in the past" card, but the additional, "I don't remember it happening that way" trump card. And in all honesty, due to various health and drug-related issues, she may not remember her dangerous, selfish actions. But I DO. They affected me and my family. They hurt me. They have left an impact on me. To ask me to brush that impact aside without addressing the core issues is a cop-out and I refuse to participate in that.