Classic · Two cities, one answer
Classic Time Zone Converter
Most people do not need a twelve-city timeline. They need one number: if it is 3 pm here, what time is it there? This is the classic time zone converter — two cities, one date, one answer — with modern IANA accuracy behind it.
Live clocks
New York
EST / EDT
07:47
EDT · UTC−4
London
GMT / BST
12:47
BST · UTC+1
Tokyo
JST
20:47
JST · UTC+9
Sydney
AEST / AEDT
22:47
AEDT · UTC+11
Clocks update every 15 seconds in your browser and always reflect the current IANA daylight saving rules.
New York → London · Sat, Oct 24
London is currently 5 hours ahead of New York. Highlighted rows fall inside typical business hours (09:00–17:00 local, weekdays) in both cities.
| New York (EDT) | London (BST) |
|---|---|
| 00:00 | 05:00 |
| 01:00 | 06:00 |
| 02:00 | 07:00 |
| 03:00 | 08:00 |
| 04:00 | 09:00 |
| 05:00 | 10:00 |
| 06:00 | 11:00 |
| 07:00 | 12:00 |
| 08:00 | 13:00 |
| 09:00 | 14:00 |
| 10:00 | 15:00 |
| 11:00 | 16:00 |
| 12:00 | 17:00 |
| 13:00 | 18:00 |
| 14:00 | 19:00 |
| 15:00 | 20:00 |
| 16:00 | 21:00 |
| 17:00 | 22:00 |
| 18:00 | 23:00 |
| 19:00 | 00:00+1 day |
| 20:00 | 01:00+1 day |
| 21:00 | 01:00+1 day |
| 22:00 | 02:00+1 day |
| 23:00 | 03:00+1 day |
Swipe the table sideways for the full day
What the classic converter looked like
The classic time zone converter was the drop-down pair: one box for "from", one for "to", a date, and a single line of output. It appeared on every office intranet and half the websites of the late 2000s, and it did exactly one job.
What made many of those versions unreliable was their data. They stored a table of fixed UTC offsets, so they were right for half the year and wrong for the other half — and they stayed wrong until someone updated the table. A converter built for London and New York would show a five-hour difference all year, which happens to be right, but the same code would show New York and Paris as six hours apart in July, when it is really four.
The classic layout, modern accuracy
The interaction here is the same one you remember: two cities and a date. The difference is underneath. Offsets are evaluated for the exact date you pick, using the IANA rules for each zone, so the answer is correct in March, in July, and in the awkward in-between weeks when one country has changed its clocks and the other has not.
The same is true of the abbreviation shown next to each city. A classic converter often printed "EST" in July because it never updated the label. Here the label is derived from the live rules, so you always see EDT, BST, CEST or whatever is actually in force.
Two-city conversion examples
These are the pairs people convert most often. The figures assume the current daylight saving state of each city, and they shift as the year changes.
- New York → London: 5 hours ahead (EST → GMT / 4 hours in summer)
- Los Angeles → New York: 3 hours ahead
- London → Berlin: 1 hour ahead (2 in summer)
- London → Dubai: 3 hours ahead (4 in summer)
- London → Delhi: 5½ hours ahead
- London → Tokyo: 8 hours ahead
- Sydney → London: 9 hours behind in southern summer, 11 in winter
When the classic view is enough — and when to switch
For a one-off question — what time is it for a colleague, when does a call land, what is the deadline here — the classic two-city conversion is exactly right. It is faster than anything else and the answer is a single line.
The moment the question becomes "when can all five of us talk", a single pair is no longer enough. That is when the timeline earns its keep: add every city, and the same page shows the shared working window, the weekends and the best slots. You do not have to choose between the two views — the classic answer is one click on the timeline, and the timeline is one click from the classic table above.
Frequently asked questions
What is a classic time zone converter?
The traditional layout of two city pickers, one date field and a single converted time. It answers one question — what time is it in the other city — and it is the fastest way to get a single answer.
How do I convert one time from one city to another?
Pick the source city and the target city, choose the date, and read the result. Internally it adds the UTC offset difference for that date, so a 09:00 start in New York becomes 14:00 in London in winter and 13:00 in summer.
Why do older time zone converters give the wrong answer?
Because they stored fixed UTC offsets instead of daylight saving rules. Half of the year those offsets are right and the other half they are an hour out, and the tables were often never updated. A converter that reads live IANA rules is correct on every date without maintenance.
Does the classic converter handle daylight saving?
Yes. The offset and the abbreviation are both evaluated for the specific date you choose, including the years when a country has changed its rules or does not observe daylight saving at all, such as Arizona, Iceland and most of Brazil.