You can use hand sanitizer as many times as you want too through the day without washing your hands with water and regular soap.
However it's recommended to only use hand sanitizer when there's no water available and where you need to clean your hands.
So you should only really use the hand sanitizer when you need to wash your hands and no water is available or no sink is available at that time.
Around 4 to 5 times per day of use of hand sanitizer is what is recommended but you can use it more often if needed.
Be aware though that if you do use hand sanitizer and then need to use your hands to eat something such as a sandwich, chips etc that the hand sanitizer that remains on your hands can transfer to the food and you'll taste it when you eat the food.
Yes that has happened to me so I make sure now to wash my hands with water and regular soap to remove the hand sanitizer before handling any food.