Hello,is it best to book tickets online or can you just come on the day?Also what is the best time to see this ?not sure if i should come the day or the night

"CityPASS®: Hi! I am referring to CityPASS®. Do holders of CityPASS® who wish to visit Top of the Rock observation deck have the ability to make a reservation for BOTH a date and a time, so that we do not need to come down in person to obtain the NEXT available ticket-time like holders of other passes (i.e. NY Pass, Explorer Pass, or Sightseeing Pass)? I would like to seek clarification on this because a page on TOTR website allows CityPASS® holders to enter their (a) CityPASS® Number, (b) Date of Visit, and (c) Time of Visit. It gives me the impression that CityPASS® holders are able to do so, and after making that online reservation, they are given a timed-entry ticket and can simply walk in and enjoy the attraction on that reserved date and time. NY Pass/Explorer Pass/Sightseeing Pass: Whereas, for holders of NY Pass, Explorer Pass, or Sightseeing Pass, a page on TOTR website states "NY Pass, Explorer Pass, and Sightseeing Pass must be redeemed in person at our box office. Guests may be ticketed for the next available ticket-time or may choose a future date and time." For your advice, please. Thank you!