Timing of H4 dependants going to US

I’m in the process of getting my H1b petition approved by my employer. My question is that if I apply for my spouse and child’s H4 right now and take them along for the interview, can they come to the US at a later date, say after 4 months?

Yes, it is possible for H-4 dependents to travel at a later date than the H-1 applicant.