Adelaide is typically 14.5 to 16.5 hours ahead of New York, depending on daylight saving time in both cities. When it's 9:00 AM in New York, it's around 11:30 PM the same day in Adelaide (during EST/ACDT).
The time difference varies throughout the year because both cities observe daylight saving time but in opposite seasons (Northern vs Southern Hemisphere). Adelaide is on ACST/ACDT (UTC+9:30/+10:30), while New York uses EST/EDT (UTC-5/-4).
Optimal meeting window: 8:00 PM - 11:00 PM Adelaide time (approximately 6:00 AM - 9:00 AM New York). Evening calls from Adelaide catch early morning in New York.
The significant time difference means one party will always be calling outside normal business hours. Consider alternating who takes the inconvenient time slot for regular meetings.