I don't have a scheduled time to fast even though I should at least once a week so I can stay strong in the Lord and put down my flesh more.
I have fasted recently with my church for different things- such as to break the bands of wickedness, to set the people free that are in the church and also called to be there. Fasting for our church to complete the call God has placed on it. Fast against the spiritual warfare, demons, devils, attacks,sickness and such.
Mostly are fasts line up to the Daniel fast- no sweet bread/bread, no meat and we already don't drink strong drink.
We fast for God to come in and loose us from evil and in turn God answers and strengthens us to be able to obey Him more - So we can stand, live not die and declare the works of the Lord.
Their are many promises with fasting that God has promised In Isaiah 58.
After fasting and prayer God does turn the stuff around just as He has promised!!
Remember fasting without prayer is just going hungry!:)