What does Buddhism mean by heaven and earth opening heaven?

Tiancang Day is also called warehouse exploration day, warehouse exploration day and warehouse exploration festival. It is the 25th day of the first month every year, which is an ancient festival that farmers generally observe. This is the morning of this day (before the sun rises). Draw several big circles in your yard with plant ash or fire ashes. All kinds of grains and miscellaneous grains are placed in the middle of the circles, symbolizing the bumper harvest this year, implying good weather and praying for God's gift. Because it is the custom to set off firecrackers after the first day of the first lunar month, generally after this festival (followed by the dragon raising its head on February 2), it means that the new year has passed and it is time to start a new year's struggle.

I'm really ashamed of Warehouse Day. I didn't know it yet. According to the laws of the lunar calendar, it seems that there must be a warehouse in the sky.

According to Shou Kang Baojian, the opening dates of Tiandi Warehouse are 25th of March, 20th of March, 6th of April, 6th of May and 6th of November.