What is the cheapest day to buy Amtrak tickets?

What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?What is the cheapest day to buy Amtrak tickets?