What Time Zone Is Slough In?
Slough operates on Europe/London, abbreviated as GMT, which is currently UTC+00:00 from Coordinated Universal Time. The IANA Time Zone Database (also known as the tz database or zoneinfo) records this under the identifier Europe/London. That identifier is what your phone, laptop, and every major web service uses when they display a localized time for Slough.
The designation Europe/London follows the IANA convention of naming zones after the largest city in that timezone region. This naming is geographic, not political, it reflects where the zone is observed, not which government controls it. The full record for this zone, including historical UTC offsets and past DST rule changes, is publicly available in the Wikipedia list of tz database time zones.
UTC Offset: Slough vs. The World
The current UTC offset in Slough is UTC+00:00. This means Slough time is equal to Coordinated Universal Time. To quickly convert: if it's 12:00 UTC right now, it's 12:49 local time in Slough.
Relative to other major cities: Slough is 5 hours ahead of New York, and 0 hours ahead of London (including any DST difference currently in effect). These differences can shift by one hour during DST transitions, which occur on different dates in different regions.
Business Hours in Slough
Standard business hours in Slough run from 09:00 to 18:00 local time (Europe/London). In UTC, that window is 09:49 to 18:49 UTC. If you're trying to schedule a call with someone in Slough:
- From New York: the Slough business day runs 04:49 to 13:49 New York time.
- From London: the Slough business day runs 09:49 to 18:49 London time.
Use the hour-by-hour conversion table above for the full 24-hour breakdown.
Daylight Saving Time in Slough
The DST indicator above shows whether Slough currently observes Daylight Saving Time. When DST is active, clocks advance by one hour, shifting the UTC offset by +1 and changing the abbreviation (for example, from EST to EDT in New York). When DST ends, clocks fall back and the offset returns to its standard value.
Not all countries observe DST. Japan, China, India, most of Africa, and several other nations maintain a fixed offset year-round. Whether Europe/London observes DST, and the exact dates of transitions, is governed by the rules stored in the IANA Time Zone Database , the same source your phone uses. The Wikipedia article on Daylight Saving Time provides a global map and country-by-country breakdown of DST observance.
Sunrise and Sunset in Slough
Today in Slough (51.5°N, 0.6°W), sunrise is approximately 06:44 and sunset is approximately 17:44 local time (Europe/London). These times are calculated using the Spencer equation for solar declination and apply to today's date. Latitude significantly affects day length: cities near the equator see roughly 12 hours of daylight year-round, while high-latitude cities experience dramatic swings, midsummer days can exceed 20 hours near the Arctic Circle, while midwinter days shrink to under 4 hours. At 51.5° latitude, Slough's day length varies substantially, expect notable differences between the longest and shortest days of the year.
Best Time to Call Slough from Abroad
Standard business hours in Slough run 09:00 to 18:00 local time (Europe/London). For international callers, the ideal window is 10:00 to 16:00 Slough time : after the morning rush and before the end-of-day slowdown. In UTC, this translates to 10:49 to 16:49 UTC. Avoid calling before 09:00 or after 20:00 Slough time, these windows fall outside acceptable business etiquette in most professional settings. If you are calling from New York,Slough business hours correspond to 04:49 to 13:49 Eastern time. From London, that same window is 09:49 to 18:49 GMT/BST.
Slough Time vs Major World Cities
Right now, Slough (UTC+00:00) is offset from major business hubs as follows:
- New York: Slough is 5 hours ahead of New York right now (UTC-05:00).
- London: Slough is the same time as London right now (UTC+00:00).
- Dubai: Slough is 4 hours behind Dubai right now (UTC+04:00).
- Singapore: Slough is 8 hours behind Singapore right now (UTC+08:00).
- Tokyo: Slough is 9 hours behind Tokyo right now (UTC+09:00).
- Sydney: Slough is 11 hours behind Sydney right now (UTC+11:00).
These differences shift by one hour during DST transitions, which occur on different dates in different regions. Always verify the current offset before scheduling.
Geographic Location of Slough
Slough sits at 51.5095°N, -0.5954°W. Solar noon, the moment the sun reaches its highest point, occurs at approximately 12:49 local time, when the sun crosses the meridian above Slough. The IANA timezone Europe/London groups Slough with nearby cities that share the same legal time, even if they sit at slightly different longitudes and therefore experience solar noon at slightly different moments. Zone boundaries are drawn along political borders and transportation corridors, not strict meridian lines.
Slough: Size, Population, and Location
Slough has a population of approximately 164,793 people, placing it among significant regional cities. The city sits at 51°30'N, 0°35'W (decimal: 51.5095°, -0.5954°),51.5 degrees north of the equator.
At 51.5° latitude, Slough experiences significant seasonal variation in day length, high-latitude cities can see 5-7 hours of daylight in midwinter and 16-20+ hours near the summer solstice. Today, Slough sees sunrise at 06:44 and sunset at 17:44 local time. The IANA timezone Europe/London groups Slough with nearby cities that share the same legal clock, even if they sit at slightly different longitudes with marginally different solar noon times.
Working Hours Overlap: Slough and Key Partners
Slough's standard working day (09:00–18:00 local, Europe/London) translates to different hours for common international partners:
- San Francisco (America/Los_Angeles): Slough's workday runs 01:49 to 10:49 Pacific time.
- Berlin (Europe/Berlin): Slough's workday runs 10:49 to 19:49 Central European time.
Overlap windows, times when both cities are within 09:00–18:00, are the practical window for real-time collaboration. Use the time difference tool on this site to find the shared working window for any pair of cities.