Most charts and satellite images are timestamped in "UTC" (Coordinated Universal Time) or "Z", which are equivalent to GMT (Greenwich Mean Time). To convert these times to local Australian times, add the time difference between your Australian time zone and GMT to these times:

For TAS, VIC, NSW, ACT and QLD, add 10 hours. e.g. 0000 UTC = 1000 (10 a.m.) EST
1200 UTC = 2200 (10 p.m.) EST
1800 UTC = 0400 ( 4 a.m.) EST next day

For SA and NT add 9.5 hours. e.g. 0000 UTC = 0930 (9.30 a.m.) CST
1200 UTC = 2130 (9.30 p.m.) CST
1800 UTC = 0330 (3.30 a.m.) CST next day

For WA add 8 hours. e.g. 0000 UTC = 0800 (8 a.m.) WST
1200 UTC = 2000 (8 p.m.) WST
1800 UTC = 0200 (2 a.m.) WST next day

Don't forget that daylight saving adds an extra hour to the difference between Australian times and GMT. So, during daylight saving, the difference for NSW, ACT, VIC and TAS is 11 hours instead of 10, and the difference for SA is 10.5 hours instead of 9.5.

QLD and NT do not participate in daylight saving.

To get a feel of the current time of day check this website: Day and Night World Map