This is going to vary WIDELY based on experience and skill. By hand, it will take ME 10-15 "heats", and about 20-30 mins. With my air hammer, I can make the same blade in about 4-7 "heats" and in 10 mins or less.
That being said, this is an area where quality is far more important than quantity, meaning that it is far more important to take your time, develop good habits, watch the level of the "heats", and create the best quality you can, always seeking to improve with each successive blade. Anyone can heat a piece of steel, whack it a few times with a hammer, and call it "forged". To bring out the achievable qualities possible in a forged blade requires skills and knowledge that are gained through experience.