KST
Korea Standard Time
GMT +9
12am
3am
6am
9am
12pm
3pm
6pm
9pm
MST
Mountain Standard Time
GMT -7
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

KST is 16 hours ahead of MST. KST uses GMT +9, and MST uses GMT -7 for this comparison.

For example, 9:00 pm KST is 5:00 am MST. Use the converter above to adjust the date or time and create a shareable meeting link.

Best meeting overlap: 8:30am-9:30am KST, which is 4:30pm-5:30pm MST (previous day).

MST is a fixed UTC-7 standard-time offset. For current Mountain Time, compare KST to MDT.

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

Time Difference

Korea Standard Time is 16 hours ahead of Mountain Standard Time
9:00 pm21:00 in KST is 5:00 am05:00 in MST

KST to MST call time
Best time for a conference call or a meeting is between 8:30am-9:30am in KST which corresponds to 4:30pm-5:30pm in MST (previous day)

9:00 pm21:00 Korea Standard Time (KST). Offset UTC +9:00 hours
5:00 am05:00 Mountain Standard Time (MST). Offset UTC -7:00 hours

9:00 pm21:00 KST / 5:00 am05:00 MST

KSTMST
12am (midnight)8am
1am9am
2am10am
3am11am
4am12pm (noon)
5am1pm
6am2pm
7am3pm
8am4pm
9am5pm
10am6pm
11am7pm
12pm (noon)8pm
1pm9pm
2pm10pm
3pm11pm
4pm12am (midnight)
5pm1am
6pm2am
7pm3am
8pm4am
9pm5am
10pm6am
11pm7am
00:0008:00
01:0009:00
02:0010:00
03:0011:00
04:0012:00
05:0013:00
06:0014:00
07:0015:00
08:0016:00
09:0017:00
10:0018:00
11:0019:00
12:0020:00
13:0021:00
14:0022:00
15:0023:00
16:0000:00
17:0001:00
18:0002:00
19:0003:00
20:0004:00
21:0005:00
22:0006:00
23:0007:00

Korea Standard Time

Offset: KST is 9 hours ahead Greenwich Mean Time (GMT) and is used in Asia

Countries using this time zone: Korea (North), Korea (South)

Principal Cities: The largest city in the KST time zone is Seoul in South Korea, with about 10.349 million people. Other major cities in this time zone include Busan, Pyongyang, Incheon, Daegu.

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

KST Time Zone Geo Map
KST timezone map

KST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +09 - basic short
  • +0900 - basic
  • +09:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0900 - sign character (+) followed by a four digit time providing hours (09) and minutes (00) of the offset. Indicates an offset of nine hours to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • India - Military abbreviation for KST
  • I - short form of 'India'
IANA/Olson: Reflects KST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • Asia/Pyongyang
  • Asia/Seoul
  • ROK
KST Abbreviation: Several time zones share KST abbreviation and it could refer to these time zones
  • Korea Standard Time - UTC +9
  • Pyongyang Time - UTC +8:30
Time zones with the GMT +9 offset:
  • AWDT - Australian Western Daylight Time
  • CHOST - Choibalsan Summer Time
  • I - India Time Zone
  • IRKST - Irkutsk Summer Time
  • JST - Japan Standard Time
  • KST - Korea Standard Time
  • PWT - Palau Time
  • TLT - East Timor Time
  • ULAST - Ulaanbaatar Summer Time
  • WIT - Eastern Indonesian Time
  • YAKT - Yakutsk Time

Mountain Standard Time

Offset: MST is 7 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries using this time zone: Canada, Mexico, United States

Principal Cities: The largest city in the MST time zone is Phoenix in the United States, with about 1.446 million people. Other major cities in this time zone include Calgary, Edmonton, El Paso, Denver.

French: HNR - Heure Normale des Rocheuses

Spanish: MT - Zona PacĂ­fico

MST Time Zone Geo Map
MST timezone map

Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Mountain Daylight Time (MDT).

Daylight saving time clock moves back for one hour from 2am to 1amStart: Mountain Standard Time (MST) started on Sunday, November 2, 2025 at 2:00 am local time and clocks were set one hour back to Sunday, November 2, 2025, 1:00 am. Standard time starts annually on the first Sunday of November.

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Mountain Standard Time (MST) ends on Sunday, March 8, 2026 at 2:00 am local time and clocks are set one hour forward to Sunday, March 8, 2026, 3:00 am local daylight time instead. Standard time ends annually on the second Sunday of March.

MST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -07 - basic short
  • -0700 - basic
  • -07:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0700 - sign character (-) followed by a four digit time providing hours (07) and minutes (00) of the offset. Indicates an offset of seven hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Tango - Military abbreviation for MST
  • T - short form of 'Tango'
IANA/Olson: Reflects MST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Boise
  • America/Cambridge_Bay
  • America/Ciudad_Juarez
  • America/Creston
  • America/Dawson
  • America/Dawson_Creek
  • America/Denver
  • America/Edmonton
  • America/Fort_Nelson
  • America/Hermosillo
  • America/Inuvik
  • America/Mazatlan
  • America/Phoenix
  • America/Shiprock
  • America/Whitehorse
  • America/Yellowknife
  • Canada/Mountain
  • Canada/Yukon
  • MST
  • MST7MDT
  • Mexico/BajaSur
  • Navajo
  • US/Arizona
  • US/Mountain
Time zones with the GMT -7 offset:
  • MST - Mountain Standard Time
  • PDT - Pacific Daylight Time
  • YST - Yukon Standard Time
  • T - Tango Time Zone