No any particular visiting hours here .. from sunrise to sunset you can visit. normally you can say 8 am to 6 pm. bird sanctuary stay open all the days expect some months in monsoon. any day you can come. it's a world Heritage Site approved by unesco. situated on bharatpur jaipur highway
It is a unesco world heritage site filled with grasslands, lot of flora and abundant fauna. This sanctuary is popular for viewing migratory birds. This park is open from 6am to 6pm everyday. There are two best tunes to visit the park august to October is the second best time. There is an entrance fee, while there are guides to take you around. Some best places to visit near this park I will share, see if it is suitable for your travel.
Bharatpur palace Deeg palace Lohargarh fort
Fateh burj Jaipur and Agra are comparatively nearby places to visit.
Kindly check the above Tripoto link for more details.