For two or more hours at a time, many days.
You have indicated that...
Your baby cries for two or more hours a day for several days
What you can do
If he cries for two or more hours a day and cannot be consoled, he might have colic. Colic can begin at two to three weeks; it is rare to continue after three months.
When he begins to cry, try to soothe him with your normal routine. If that does not quiet him, try:
Gently bouncing or walking him, or taking a car ride
Creating white noise (quiet music, vacuum cleaner)
As much as you want to comfort your baby, if he has colic, there may be nothing you can do that will make him happy. And no matter how upbeat a mom you are, the crying can really wear you down. A good support system will give you a much-needed break when your baby's crying overwhelms you. Ask for help from your partner or a family member to give you relief when you need it. Get sleep when you can, and try to remember — it is temporary.
If the recommendations above do not reduce your baby's crying, discuss it with your health care professional.