The Pandarinatha Thirumanjanam happens in honour of His nakshatra naal, which is Rohini nakshatram.
At 930pm (supposed to be)/ 1045pm (when it actually begins) there was a Perumal, Venugopala, Navaneethakrishnan and baby Thavazhum Kannan Thirumanjanam. Finishes by 1145. We leave by midnight as the rest wait on for the moon to grow visible as it is only then that the puja will be completed.
Observation made by the Draupadi Amman temple priest at a different moment but relevant here: Gokulashtami and Krishna Jayanti fall this year on the same date. So that means that some years they fall on different dates? How? The explanation is that people observe the moment differently. Most observe the ‘tithi’ – the ashtami (eighth day of the month) of the month Shravan/Aavani, in which case it is by its very name associated with the tithi, Gokulashtami or Janmashtami. But there are others who observe the Aavani birth star which is Rohini, and they call it Krishna Jayanti (or Sri Jayanti).