変換方法 Time Zones

Scheduling a meeting across continents, calculating when an event airs in your location, or knowing when to call someone overseas—time zone conversion is a daily necessity in our connected world. This guide explains how to convert between time zones accurately.

Step-by-Step Time Zone Conversion

Method 1: Using UTC Offsets

1. Find the UTC offset of your starting time zone
2. Find the UTC offset of your target time zone
3. Calculate the difference
4. Add (going east) or subtract (going west) from your starting time

Example

Convert 2:00 PM Los Angeles (PST, UTC-8) to Berlin (CET, UTC+1):

1. LA is UTC-8, Berlin is UTC+1
2. Difference: 1 - (-8) = 9 hours
3. 2:00 PM + 9 hours = 11:00 PM Berlin

Major Time Zones Reference

Daylight Saving Time (DST)

Many regions shift clocks forward in spring and back in fall, changing UTC offsets:

DST Complications

• DST dates differ between countries
• Southern hemisphere shifts opposite to northern
• Some regions don't observe DST (Arizona, most of Asia)
• Check current offset during transition periods

Business 時間 Overlap

Finding overlap between time zones for meetings:

Method 2: Through UTC

1. Convert your local time to UTC
2. Convert UTC to the target time zone

Example

Convert 3:00 PM 変換先kyo (JST, UTC+9) to Los Angeles (PST, UTC-8):

1. 変換先kyo to UTC: 3:00 PM - 9 hours = 6:00 AM UTC
2. UTC to LA: 6:00 AM - 8 hours = 10:00 PM (previous day)

So 3:00 PM Thursday 変換先kyo = 10:00 PM Wednesday Los Angeles

まとめ

Converting time zones requires knowing the UTC offset of both locations and accounting for daylight saving time. The basic formula: add or subtract the hour difference between zones. When scheduling internationally, always specify the time zone (e.g., "3 PM EST" or "3 PM UTC-5") and double-check DST status during spring and fall transitions.

関連記事

• Time Zones and UTC: How the World Tells Time
• Work 時間 Calculations: Converting Time to Pay