digraph G {
 rankdir=TB
 node [shape=box, fontsize=9, height=0.1, width=0.05 ]
 edge [arrowsize=0.5, len=0.1]
"Thermostat\n"->"Time\nTemperature\n"
"Time\nTemperature\n"->"Time\n"
"Time\nTemperature\n"->"Temperature\n"
"Time\n"->"Date\nHour\nseason\noperation\n"
"Date\nHour\nseason\noperation\n"->"Date\nHour\n"
"Date\nHour\nseason\noperation\n"->"season\noperation\n"
"Date\nHour\n"->"Date\n"
"Date\nHour\n"->"Hour\n"
}