How to select the Sentinel 3 day and night temperature images for a specific region

Hello all,

I am having some difficulty selecting Sentinel-3 land surface temperature (LST) images for the Yanco region in Australia. From what I understand, Sentinel-3 timestamps are provided in UTC, which differs by approximately 10–11 hours from Australian local time.

Based on this, if the UTC time is 12:00 noon, it would correspond to around 10:00–11:00 PM in Yanco. I am trying to calculate the diurnal temperature difference (i.e., the difference between daytime and nighttime temperatures) for specific dates, but I am confused about how to handle this time difference.

For example, if I want to collect data for January 3, the available images are timestamped at 12:55:26.037000Z and 23:32:50.929000Z. The 12:55:26.037000Z image corresponds to nighttime in Yanco, while the 23:32:50.929000Z image corresponds to the following morning in local time.

In this case, to calculate the diurnal temperature difference for January 3, should I consider the 23:32:50.929000Z image from January 2 as the daytime LST for January 3, and the 12:55:26.037000Z image from January 3 as the nighttime LST?

I would appreciate any clarification on the correct approach.

Thank you.