Every Day is a New Day
Nature has its own cycles. The cycle of time in which the earth makes a complete rotation on its axis is called a day. Although, a day is a repetitive natural phenomenon yet no day is same. Every day is a new day because it is extremely different, a new beginning and a new opportunity.
Firstly, every day is a different day. It has a different name, different date and different possibilities. When Manolin reminds Santiago of his an erstwhile unlucky spell of 87 days, Santiago says, "It could not happen twice". Thus no day is like bygone days. It is absolutely new.
Secondly, every day is a new beginning. A man is reborn every day. It is the first day of the rest of his life. It is a clean slate. If man performs bad of good deeds the day before, the canvas is wiped clean as soon as he wakes up the next morning.
Thirdly, every day is a new opportunity. The chief beauty about a new day is that no man can consume it in advance. Every new day lies ready for him, as perfect, as unspoiled. So man should be optimistic about every day. In fact, Santiago rightly hopes that 85th will be a lucky day.