San Juan, Puerto Rico to ADT Time Converter

Updating current time…
San Juan
Puerto RicoAST
UTC−4
12am
3am
6am
9am
12pm
3pm
6pm
9pm
ADT
Atlantic Daylight Time
UTC−3
1h ahead
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

Selected conversion

8:00 am08:00 AST (UTC-4), Oct 15, 2026 = 9:00 am09:00 ADT (UTC-3), Oct 15, 2026

San Juan is 1 hour behind ADT.

How the time difference changes

For most of the year, San Juan, Puerto Rico is 1 hour behind ADT. From Nov 1, 2026 to Mar 14, 2027, San Juan, Puerto Rico and AST have the same time.

For most of the year, working hours of 9:00 am to 6:00 pm in San Juan, Puerto Rico correspond to 10:00 am to 7:00 pm in ADT. At other times of the year, working hours of 9:00 am to 6:00 pm in San Juan, Puerto Rico correspond to 9:00 am to 6:00 pm in AST.For most of the year, working hours of 09:00 to 18:00 in San Juan, Puerto Rico correspond to 10:00 to 19:00 in ADT. At other times of the year, working hours of 09:00 to 18:00 in San Juan, Puerto Rico correspond to 09:00 to 18:00 in AST.

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

Time Difference

AST (Atlantic Standard Time) is 1 hour behind Atlantic Daylight Time.
8:00 am08:00 in San Juan, Puerto Rico is 9:00 am09:00 in ADT

San Juan to ADT call time
Best time for a conference call or a meeting is between 9am-5pm09:00-17:00 in San Juan which corresponds to 10am-6pm10:00-18:00 in ADT

8:00 am08:00 AST (Atlantic Standard Time) (San Juan, Puerto Rico). Offset UTC -4:00 hours
9:00 am09:00 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours

8:00 am08:00 San Juan, Puerto Rico / 9:00 am09:00 ADT

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Hourly time comparison
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San Juan Time Zone and Facts

Time Zone

Abbreviation / Offset
AST – Atlantic Standard Time, UTC-4 (no daylight saving time)

San Juan Facts

Country
Puerto Rico
Alternative Names
Caparra, Ciudad de Puerto Rico, Portorico, Prico, Puerto Rico, SJU, Saint Iuan, Saint John de Porto Rico, Sainte Jean de Porto-rico, San Chouan, San Chuanas, San Huan, San Ian de Porto Rico, San Ioanni, San Jean de Portorico, San Juan, San Juan Batista de Puerto Rico, San Juan Bautistade de Puerto Rico, San Juan de Puerto Rico, San Khuan, San Xoan, San Xoán, San Xuan, San-Juano, San-Khuan, Sanhuana, The City of Saint John, Ville de Porto-Rico, Ville de Sainte Jean de Porto Rico, can van, saenhwan, san hwn, san khwan, san-khuani, sana hu'ana, sana huraana, sanfuan, sanhuan, sheng hu an, Σαν Χουάν, Сан Хуан, Сан-Хуан, Սան Խուան, סן חואן, سان خوآن, سان خوان, सान हुआन, সান হুৱান, ਸਾਨ ਹੁਆਨ, சான் வான், ซานฮวน, სან-ხუანი, サンフアン, 圣胡安, 산후안, 샌환
Population
418,140
Currency
Dollar (USD)
Geographic Coordinates
18° 27' N Latitude / 66° 06' W Longitude
More About San Juan
San Juan local time and city facts

Atlantic Daylight Time

Offset: ADT is 3 hours behind Greenwich Mean Time (GMT).

Countries using this time zone: Bermuda, Canada, Greenland

Principal Cities: The largest city in the ADT time zone is Halifax in Canada, with about 471,559 people. Other major cities in this time zone include Sydney, Moncton, Saint John, Fredericton.

French: HAA - Heure Avancée de l'Atlantique

Map of the areas on Atlantic Daylight Time (ADT)
ADT part of the year

Today all shaded areas are on ADT.

Open the world time zone map© OpenStreetMap

Daylight Saving: Atlantic Daylight Time (ADT) is a daylight saving/summer time zone. During winter, some places set clocks back one hour and observe Atlantic Standard Time (AST).

123456789101112Start: Atlantic Daylight Time (ADT) started on Sunday, March 8, 2026 at 2:00 am02:00 local time and clocks were set one hour forward to Sunday, March 8, 2026, 3:00 am03:00. Daylight saving starts annually on the second Sunday of March.

123456789101112End: Atlantic Daylight Time (ADT) ends on Sunday, November 1, 2026 at 2:00 am02:00 local time and clocks are set one hour back to Sunday, November 1, 2026, 1:00 am01:00 local standard time instead. Daylight saving ends annually on the first Sunday of November.

See upcoming clock changes worldwide.

ADT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -03 - basic short
  • -0300 - basic
  • -03:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0300 - sign character (-) followed by a four digit time providing hours (03) and minutes (00) of the offset. Indicates an offset of three hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Papa - Military abbreviation for ADT
  • P - short form of 'Papa'
IANA/Olson: Reflects ADT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Glace_Bay
  • America/Goose_Bay
  • America/Halifax
  • America/Moncton
  • America/Thule
  • Atlantic/Bermuda
  • Canada/Atlantic
Time zones with the GMT -3 offset:
  • ADT - Atlantic Daylight Time
  • PMT - Pierre & Miquelon Standard Time
  • PMST - Pierre & Miquelon Standard Time
  • AMST - Amazon Summer Time
  • ART - Argentina Time
  • BRT - Brasília time
  • CLST - Chile Summer Time
  • FKST - Falkland Islands Summer Time
  • GFT - French Guiana Time
  • P - Papa Time Zone
  • PYST - Paraguay Summer Time
  • SRT - Suriname Time
  • UYT - Uruguay Time
EST to ISTGMT to ESTPST to ESTEST to GMTPST to GMT