Yesterday, today and tomorrow, the three-day life in this poem refers to

1 Yesterday, today and tomorrow refer to the past, present and future. Warn us not to lose precious light and shade, and cherish time. Grasping the present is to create a beautiful yesterday for tomorrow and a beautiful memory for the future. Yesterday-has passed, gone forever; Today-it is also at your feet, shortening tomorrow minute by minute-is the future and hope, it is calling and waving to you.