Current Time Calculator — Free Online World Clock Tool

How to Use the Current Time Calculator

1. Select a time zone: Use the dropdown menu to choose any time zone from UTC-12 through UTC+14. Each option includes a representative city to help you identify the correct zone. The default is UTC+0 (London/Greenwich).
2. View the live clock: The results panel displays a large digital clock showing the current time in your selected zone. The clock updates every second in real time. Below the clock, you can see the current day of the week and full date, plus both 24-hour and 12-hour format representations.
3. Compare with reference times: On the left side, your local device time and UTC time are displayed with their respective dates and day names. This three-way comparison makes it easy to see the relationships between your local time, universal time, and any world time zone at a glance.

The clock runs continuously while the page is open. Switch between time zones instantly to check the time in different cities around the world. For converting a specific time between zones, use our time zone calculator.

Time Zone Conversion Formula

Variables Explained

• Current UTC: The current Coordinated Universal Time, derived from your device's system clock by removing the local time zone offset. This is the universal reference point from which all zone times are calculated.
• Target Offset: The selected time zone's offset from UTC in hours. Positive values are east of Greenwich (ahead of UTC), negative values are west (behind UTC). For example, Tokyo is +9 and New York is -5.
• Local UTC Offset: Your device's time zone offset from UTC, obtained from JavaScript's getTimezoneOffset() method. This returns the offset in minutes (negative for east of UTC), which is converted to hours.
• Target Time: The current time in the selected time zone, displayed as a continuously updating digital clock.

Step-by-Step Example

If your local time is 15:30 EST (UTC-5) and you select Tokyo (UTC+9):

1. Local time: 15:30 with offset -5 hours
2. Convert to UTC: 15:30 + 5:00 = 20:30 UTC
3. Apply target offset: 20:30 + 9:00 = 29:30
4. Normalize: 29:30 - 24:00 = 05:30 (next day)
5. Result: 05:30 the next day in Tokyo (UTC+9)

When it is 3:30 PM in New York, it is 5:30 AM the next day in Tokyo. Tokyo is 14 hours ahead of Eastern Standard Time.

Practical Examples

Example 1: Nina's International Business Calls

Nina is a sales manager in Chicago (UTC-6) who regularly calls clients in London (UTC+0), Dubai (UTC+4), and Singapore (UTC+8). Before making calls, she checks the current time in each city:

• Chicago: 09:00 (her local time)
• London: 15:00 (6 hours ahead, within business hours)
• Dubai: 19:00 (10 hours ahead, end of business day)
• Singapore: 23:00 (14 hours ahead, too late to call)

Nina calls London first (still business hours), then Dubai (catching them before they leave). She schedules the Singapore call for 7:00 PM her time (9:00 AM Singapore the next day). The live clock helps her avoid calling at inappropriate hours.

Example 2: Alex's Livestream Scheduling

Alex is a content creator in Los Angeles (UTC-8) planning a livestream that should reach viewers in North America and Europe. He checks current times to find the best slot:

• Los Angeles: 17:00 (5 PM, after work for West Coast)
• New York: 20:00 (8 PM, prime viewing time East Coast)
• London: 01:00 (1 AM, too late for most UK viewers)

Alex decides to stream earlier, at 11:00 AM Los Angeles time:

• Los Angeles: 11:00 (late morning, feasible for West Coast)
• New York: 14:00 (2 PM, afternoon viewers)
• London: 19:00 (7 PM, prime evening time for UK)

By shifting to a morning stream, Alex captures the European evening audience while still being accessible to American viewers.

Example 3: Yuki's Server Maintenance Window

Yuki is a systems administrator in Tokyo (UTC+9) who needs to schedule server maintenance during the lowest traffic period. The company's users are primarily in Japan, the US West Coast, and Germany:

• Maintenance window: 03:00-05:00 Tokyo time
• US West Coast (UTC-8): 10:00-12:00 (previous day, business hours)
• Germany (UTC+1): 19:00-21:00 (previous day, evening)

Yuki realizes that 3 AM Tokyo time falls during US business hours. She adjusts to 05:00-07:00 Tokyo time instead (12:00 PM-2:00 PM PDT, 21:00-23:00 CET), which still has some traffic but minimizes impact during the Japanese workday while avoiding peak US hours. For tracking project deadlines across time zones, the time difference calculator helps compare specific times.

World Time Zones Overview Table

Tips and Complete Guide

Using the World Clock for Remote Work

Remote teams spread across time zones face unique coordination challenges. Establishing "core hours" — a window when everyone is expected to be available — is essential. For a team spanning San Francisco, London, and Mumbai, the core hours might be 09:00-11:00 London time (01:00-03:00 PST, 14:30-16:30 IST). Use this calculator to quickly check whether a colleague is currently within their working hours before sending an urgent message or scheduling a meeting.

Understanding Atomic Time and NTP

The time displayed by this calculator comes from your device's system clock, which is typically synchronized with Network Time Protocol (NTP) servers. These servers maintain time using atomic clocks — the most accurate timekeeping devices, losing only about one second every 100 million years. Atomic time is based on the vibration of cesium-133 atoms (9,192,631,770 vibrations = 1 second). While your device clock may drift slightly between synchronizations, it is generally accurate to within a few dozen milliseconds after a successful NTP sync.

Time Zones and International Events

Major international events like the Olympics, FIFA World Cup, and tech product launches specify times in the host city's local zone. Use this calculator to convert event times to your local zone. For recurring events like daily stock market trading sessions (NYSE: 09:30-16:00 EST, LSE: 08:00-16:30 GMT, TSE: 09:00-15:00 JST), check the live clock to know if a specific market is currently open. For astronomy-related time questions, our sunrise calculator provides location-specific solar times.

Common Mistakes to Avoid

• Not accounting for DST: Select the current offset including any DST adjustment. If a region is in summer time, its effective UTC offset changes by one hour. The calculator uses fixed offsets, so you must select the correct current offset.
• Assuming device time is correct: If your device's clock is wrong (manually set to wrong time or timezone), all displayed times will be incorrect. Verify your device has automatic time synchronization enabled in system settings.
• Forgetting date differences: Due to time zone offsets, it may be a different calendar date in the selected zone than in your local zone. Always check the displayed date alongside the time, especially when planning events or deadlines near midnight.
• Ignoring half-hour offsets: Several major zones like India (UTC+5:30) use half-hour offsets. If you only check whole-hour zones, you may miss the correct time for these regions by 30 minutes.
• Confusing similar abbreviations: IST can mean Indian Standard Time (UTC+5:30), Irish Standard Time (UTC+1), or Israel Standard Time (UTC+2). Always verify by checking the UTC offset rather than relying on abbreviations alone.

Frequently Asked Questions