How long will it take for duck to hatch?

[Kryptic]

I had a mallard hatch last night, the other one pipped. Still no progress on that egg. It was peeping this morning though so it's still alive. Is this concerning or normal?
Also, these 2 eggs were out in the cold after my hen got off the nest, (Chicken is sitting on them) So they were in the cold for about 4-6 hours maybe 5 days ago. Will this effect them? Any help and tips are great!

 

[DucksAreBest]

Yes, it's normal for them to hatch that long. Ducklings can take up to 48 hours to hatch. Colder temperature for a period of time will cause a slightly delayed hatch.