We have two excellent examples of prayer in the latter part of the Old Testament. Daniel is the more famous of the two, with his habit of praying three times a day, a habit which resulted in him being thrown to the lions from which God saved him. I like Daniel's example because it shows the devotion of a busy man. Remember, at the time of Daniel chapter 6, Daniel was the leader of a council that headed all the satraps of the kingdom of Babylon (which was subject to Persia at the time). He was, in effect, the number 2 man in the kingdom behind Darius. So he was busy.
But regardless of how busy he was, he set aside time every day to pray. This is a great example for us today with our busy lives. We always have more things that need to be done, too many things, in fact. We shouldn't (can't) allow our busy-ness to keep us away from time with our God. If necessary, schedule an appointment with God and then keep it. It's your most important appointment of the day.
The second example is less well known: Nehemiah. As I have studied through Nehemiah the thing I have noticed most is that he prayed constantly. The account doesn't mention a regular praying schedule like Daniel’s, but at every turn Nehemiah is praying. In chapter 1:5-11 he prays after hearing of Jerusalem's sad state. In 2:4 he says a quick prayer before asking the king for permission to repair the city. In 4:4-5 he prays that God will punish those hindering the work. In 4:9 he prays when he hears of them coming to attack. In 5:19 he prays for God to remember his good deeds. In 6:9 he prays for strength to continue in the work. In 6:14 he asks God to notice the evil his enemies are doing. So, he prayed when he was sad and troubled, when he was scared, angry, worried, when he wanted God to notice his good deeds, when he needed strength, when he wanted God to remember the evil deeds of evildoers. At every turn of his life, Nehemiah prayed.
Some of these prayers were lengthy. Many were short. At least one was internal and so short the king didn't notice an undue pause. Still, at every trying time, Nehemiah prayed. What would happen if we prayed every time we were scared and worried? Would our faith be stronger and our sense of peace unassailable? What if we prayed every time we were angry? Would we sin less often? If we prayed when problems arose, would the solutions seem easier? Nehemiah is an example of a man whose faith in God was so strong that he took everything—everything--to God in prayer.
So, combining the examples, we need to set aside time to pray, time to spend communing with God. We can't allow our busy lives to estrange us from God. We also need to turn to God when things happen between our "appointments". We need to take all our troubles to Him. They don't need to be long prayers, but if we cast our cares upon Him our lives will be easier and we will be better equipped to keep on the straight and narrow.
I love the LORD, because he has heard my voice and my pleas for mercy. Because he inclined his ear to me, therefore I will call on him as long as I live. Psalms 116:1-2