Time Difference: Hong Kong vs Sydney

Hong Kong (GMT+8) · Sydney (GMT+10)

Hong Kong

GMT+8

--:--:--

Sydney

GMT+10

--:--:--

Sydney and Hong Kong are in the same UTC offset

Time Difference

Hong Kong Offset

GMT+8

Asia/Hong_Kong

Sydney Offset

GMT+10

Australia/Sydney

Summary

Hong Kong and Sydney share the same UTC offset

Business Hours Overlap (9 AM – 6 PM)

9 hours overlap during standard business hours in both cities.

Hong Kong	Sydney	Overlap
9 AM	9 AM	Business hours
10 AM	10 AM	Business hours
11 AM	11 AM	Business hours
12 PM	12 PM	Business hours
1 PM	1 PM	Business hours
2 PM	2 PM	Business hours
3 PM	3 PM	Business hours
4 PM	4 PM	Business hours
5 PM	5 PM	Business hours
6 PM	6 PM	Outside

Did You Know? — Hong Kong & Sydney

Time Zone Facts: Hong Kong

•Hong Kong uses HKT (UTC+8) with no DST, permanently fixed to the same offset as Beijing, Singapore, and Taipei — making intra-APAC scheduling between these hubs straightforward.
•The Hong Kong Stock Exchange (HKEX) is the world's fifth-largest exchange by market cap; it opens at 9:30 AM HKT with a lunch break from 12:00–1:00 PM, closing at 4:00 PM HKT.
•At 22.3°N, Hong Kong is subtropical and sees about 10.8 hours of daylight in December and 13.7 hours in June — a moderate seasonal swing, with the main environmental variation being typhoon season (May–November).

Time Zone Facts: Sydney

•Sydney uses AEST (UTC+10) in winter and AEDT (UTC+11) in summer — but because Australia's seasons are reversed, Sydney observes DST from October to April, the opposite of Northern Hemisphere cities.
•The Australian Securities Exchange (ASX) in Sydney opens at 10:00 AM AEST/AEDT and closes at 4:00 PM — it is the first major exchange to open each trading day globally.
•At 33.9°S in the Southern Hemisphere, Sydney has about 9.9 hours of daylight in June (its winter) and 14.4 hours in December (its summer).

Frequently Asked Questions

Hong Kong and Sydney are in the same time zone offset, so there is no time difference between them.

There are 9 overlapping business hours (9 AM–6 PM) between Hong Kong and Sydney. Scheduling during those hours ensures both parties are in their working day.

Hong Kong and Sydney share the same UTC offset (GMT+8), so their workdays are completely synchronized — no conversion needed, identical real-time availability, and deadline alignment is automatic.

Hong Kong observes GMT+8 (Asia/Hong_Kong). A standard 9:00 AM–6:00 PM workday in Hong Kong maps to specific UTC hours — use UTC-anchored deadlines when coordinating with Hong Kong-based teammates to avoid confusion from local clock changes.

Sydney observes GMT+10 (Australia/Sydney). A standard 9:00 AM–6:00 PM workday in Sydney maps to specific UTC hours — use UTC-anchored deadlines when coordinating with Sydney-based teammates to avoid confusion from local clock changes.

If {cityA} and {cityB} follow different DST schedules — common in North America–Europe, Southern Hemisphere, or no-DST pairings — the time difference shifts by 1 hour during each transition. The 1–3 weeks between the two cities' clock-change dates create a 'gap window' that frequently catches teams off guard. The difference displayed here is always live and accounts for current DST status.

The best time to call Sydney from Hong Kong is during the 9-hour business-hours overlap window, when both cities are within their standard working day (9 AM–6 PM).

When it is midnight (00:00) in Hong Kong, it is 12 AM in Sydney.

No — Hong Kong and Sydney share the same UTC offset, so they are always on the same calendar date.

Hong Kong observes Asia/Hong_Kong (GMT+8). For async-first teams, the most reliable approach is anchoring shared deadlines in UTC rather than any local time, and defining each member's 'availability window' — typically 9:00 AM–6:00 PM Asia/Hong_Kong for Hong Kong. This eliminates confusion when DST transitions shift local clocks seasonally.

Sydney observes Australia/Sydney (GMT+10). For async-first teams, the most reliable approach is anchoring shared deadlines in UTC rather than any local time, and defining each member's 'availability window' — typically 9:00 AM–6:00 PM Australia/Sydney for Sydney. This eliminates confusion when DST transitions shift local clocks seasonally.

Yes — with 9 hours of overlapping business hours, Hong Kong and Sydney teams can hold real-time standups and synchronous collaboration daily during that window.