When growing Jalapeno peppers and they turn green they can take an additional few weeks to 4 weeks to turn from green to red.
When growing Jalapeno peppers from the plant it takes at least 150 days from planting the Jalapeno Pepper plant before the peppers turn red.
You can eat the Jalapeno peppers when they turn green but if you want to have the Jalapeno peppers turn red it will take 150 days.
But once the Jalapeno Peppers turn green and are ready to pick it takes around a month in my experience for the peppers to turn red.