The types of mosquitoes most likely to transmit EEE infection are likely to be out searching for food (an animal to bite) at dusk, the time period between when the sun sets and it gets completely dark. The exact timing of this increased activity is influenced by many factors including temperature, cloud cover, wind and precipitation and cannot be predicted precisely for any given day. Here, the approximate time of sunset and sunrise were used to establish standardized recommendations for cancellation and morning start times of outdoor activities during periods of high EEE risk.
This does not eliminate risk nor does it alleviate the need for the use of repellents or clothing for protection from mosquitoes.
Please see link for calendar of sunset times.