Confidence: It's likely to be this, but I can't be certain.
Notes: Wing shape and markings appear to be correct. There will be two 'eye' marks on the hind wing but in this picture they are concealed beneath the fore wings. The resting posture with the hind wing held slightly in front of the fore wings (similar to our poplar hawk moth) is typical for this species.
The location for this observation is within the known range of this species and the date is within the known flight period.