The answer to 'best time for patio installation' is that the ideal time is typically in the spring or fall. During these seasons, the weather is mild and the ground is more stable, making it easier and more efficient to install a patio. The spring and fall also offer the best conditions for laying concrete, pavers, or other patio materials, as the ground is not frozen or overly dry and hot.
In the spring, the ground has had time to thaw and settle after the winter, and the weather is generally dry enough to allow for proper curing of the patio materials. In the fall, the ground is still warm enough to work with, and the cooler temperatures are better suited for the physical labor involved in patio installation.