我正在运行以下Google Maps Directions API请求：
https://maps.googleapis.com/maps/api/directions/json?origin=53.8495996301,-1.46446203532&destination=53.9236806771,-1.38606898017&waypoints=via:53.8662581183,-1.44997238789%7Cvia:53.8840009077,-1.44013139071%7Cvia:53.8998229922,-1.42836848226%7Cvia:53.9095909181,-1.40235219041&DEPARTURE_TIME=1559541600&key=APIKEY
这工作正常，并且当我添加 traffic_model 参数以获得悲观的旅行时间时，可以得到我的旅行时间结果，如下所示：
https://maps.googleapis.com/maps/api/directions/json?origin=53.8495996301,-1.46446203532&destination=53.9236806771,-1.38606898017&waypoints=via:53.8662581183,-1.44997238789%7Cvia:53.8840009077,-1.44013139071%7Cvia:53.8998229922,-1.42836848226%7Cvia:53.9095909181,-1.40235219041&DEPARTURE_TIME=1559541600&traffic_model=pessimistic&key=APIKEY
我收到以下错误：
"无效请求。缺少'departure_time'参数。
我尝试将此参数放置在多个位置，但它们似乎都不起作用，并且都提供了与上述相同的错误。
任何帮助将不胜感激。
departure_time参数应为小写：
https://maps.googleapis.com/maps/api/directions/json?origin=53.8495996301,-1.46446203532&destination=53.9236806771,-1.38606898017&waypoints=via:53.8662581183,-1.44997238789%7Cvia:53.8840009077,-1.44013139071%7Cvia:53.8998229922,-1.42836848226%7Cvia:53.9095909181,-1.40235219041&departure_time=1559541600&traffic_model=pessimistic&key=YOUR_API_KEY