sukhmani sahib

Vaheguru Ji Ka Khalsa Vaheguru Ji Ki Fateh, the answer is yes; however, it's usually considered both Simran and Ardas time, (when you can fully concentrate on Vaheguru, as well as speak to him as that time the doors of Sach Khand are open fully). Amrit Vela is considered to be 3-6 A:M, (accepted; however, many Sikhs consider it 12-6 A:M), what you feel is the proper way will assist you, (there's no rules on what time to do Sukhmani Sahib). Vaheguru Ji Ka Khalsa Vaheguru Ji Ki Fateh!