HST
Hawaii Standard Time
GMT -10
12am
3am
6am
9am
12pm
3pm
6pm
9pm
Australia
AEDT
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Compare HST time with Sydney time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.

Time Difference

Hawaii Standard Time is 21 hours behind AEDT (Australian Eastern Daylight Time)
2:00 am02:00 in HST is 11:00 pm23:00 in Sydney, Australia

HST to Sydney call time
Best time for a conference call or a meeting is between 12pm-5pm in HST which corresponds to 9am-2pm in Sydney (next day)

2:00 am02:00 Hawaii Standard Time (HST). Offset UTC -10:00 hours
11:00 pm23:00 AEDT (Australian Eastern Daylight Time) (Sydney, Australia). Offset UTC +11:00 hours

2:00 am02:00 HST / 11:00 pm23:00 Sydney, Australia

HSTSydney, Australia
12am (midnight)9pm
1am10pm
2am11pm
3am12am (midnight)
4am1am
5am2am
6am3am
7am4am
8am5am
9am6am
10am7am
11am8am
12pm (noon)9am
1pm10am
2pm11am
3pm12pm (noon)
4pm1pm
5pm2pm
6pm3pm
7pm4pm
8pm5pm
9pm6pm
10pm7pm
11pm8pm
00:0021:00
01:0022:00
02:0023:00
03:0000:00
04:0001:00
05:0002:00
06:0003:00
07:0004:00
08:0005:00
09:0006:00
10:0007:00
11:0008:00
12:0009:00
13:0010:00
14:0011:00
15:0012:00
16:0013:00
17:0014:00
18:0015:00
19:0016:00
20:0017:00
21:0018:00
22:0019:00
23:0020:00

Hawaii Standard Time

Offset: HST is 10 hours behind Greenwich Mean Time (GMT) and is used in Pacific

Countries using this time zone: United States

Principal Cities: The largest city in the HST time zone is Honolulu in the United States, with about 371,657 people. Other major cities in this time zone include Pearl City, Hilo, Kailua, Waipahu.

Daylight Saving: Clocks in Hawaii Standard Time (HST) do not change for daylight saving time, so HST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter.

HST Time Zone Geo Map
HST timezone map

HST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -10 - basic short
  • -1000 - basic
  • -10:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -1000 - sign character (-) followed by a four digit time providing hours (10) and minutes (00) of the offset. Indicates an offset of ten hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Whiskey - Military abbreviation for HST
  • W - short form of 'Whiskey'
IANA/Olson: Reflects HST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Adak
  • America/Atka
  • HST
  • Pacific/Honolulu
  • Pacific/Johnston
  • US/Aleutian
  • US/Hawaii
Time zones with the GMT -10 offset:
  • HAST - Hawaii-Aleutian Standard Time
  • CKT - Cook Island Time
  • HST - Hawaii Standard Time
  • TAHT - Tahiti Time
  • W - Whiskey Time Zone

Sydney Information

Time Zone

Abbreviation / Name
AEST - Australian Eastern Standard Time
AEDT - Australian Eastern Daylight Time
UTC / GMT Offset
+10:00 hours during Australian Eastern Standard Time, currently in use.
+11:00 hours during Australian Eastern Daylight Time.
Daylight Saving Time Change
+1:00 hour - DST is NOT in use
Daylight Saving Time Starts
Daylight saving time clock moves forward for one hour from 2am to 3amSunday, October 4, 2026 at 2:00 am local time. DST starts annually on the 1st Sunday of October. Clocks are turned forward 1 hour to Sunday, October 4, 2026 at 3:00 am local daylight time instead. Also called Spring Forward or Summer Time.
Daylight Saving Time Ends
Daylight saving time clock moves back for one hour from 3am to 2amSunday, April 5, 2026 at 3:00 am local time. DST ends annually on the 1st Sunday of April. Clocks are turned backward 1 hour to Sunday, April 5, 2026 at 2:00 am local standard time instead. Also called Fall Back or switch to Winter Time.

Sydney Facts

Country
Australia
Alternative Names
SYD, Sanctus Dionysius, Sedniejos, Sek-na, Sidnef, Sidnei, Sidnej, Sidneja, Sidnejo, Sidnejus, Sidney, Sidneý, Sidni, Sidnéy, Sidnėjus, Sit-ni, Sit-nì, Syd, Sydneium, Sydney, Sydney City, Sék-nà̤, Sídney, Sîdney, Sėdniejos, citni, shidoni, sidani, sideuni, sidnei, sidni, sidniy, sydny, xi ni, xue li, Σίδνεϋ, Сиднеи, Сидней, Сиднеј, Сидни, Сідней, Сідні, Սիդնեյ, סידני, سيدنى, سيدني, سڈنی, سیدنی, ܣܝܕܢܝ, सिडनी, सिड्नी, सिद्नी, সিডনি, ਸਿਡਨੀ, સીડની, சிட்னி, సిడ్నీ, ಸಿಡ್ನಿ, സിഡ്നി, සිඩ්නි, ซิดนีย์, སིད་ནེ།, ဆစ်ဒနီမြို့, სიდნეი, ሲድኒ, ស៊ីដនីយ៏, シドニー, 悉尼, 雪梨, 시드니
Population
4,627,345
Currency
Dollar (AUD)
Geographic Coordinates
33° 52' S Latitude / 151° 12' E Longitude
International Dialing Code
+61