Adjusting range function period

I’m trying to compare current data to same period 1 year ogo.

 WeatherData = from(bucket: "Weather")
 |> range(start: v.timeRangeStart-1y, stop: v.timeRangeStop-1y )

but Influx shows an error

 type error @2:35-2:37: expected time but found duration

can somebody suggest how to formulate that?