November 4, 2011 8:39:21 PM CDT
I will answer your questions in reverse order:
1. Yes, you can tell those around you who are closer to you when fasting. Most of the times you'll need to tell them, as they might ask why you're not eating.
2. There is no rule for fasting regarding number of days. What is known is only that you don't drink or eat and you spend your time in prayer. For as long as your body can handle it. You can eat if you get sick while fasting, while still carrying on with your prayer, for example. That is ok. And if you need to do small things to help others that's ok too. Fasting is more than just prayer, it's an attitude, a focus and discipline of the mind, without distractions. So you probably won't use facebook and television. :)
3. Fasting is not compulsory, nor ignorable. Jesus does not tell his disciples "You must fast" or "You can fast if you want to". He simply says "When you fast...", meaning this practice is only natural for a christian who wants to grow spiritually. Hope it helped. PM me for more questions.