They say that "Time is the great equalizer of life", but first you have to get a grip on what time it is. In a world where we increasingly collaborate with others across 24+ time zones, we really need to effectively communicate what time an event takes place. The world is divided longitudinally into time zones. Because some countries have half hour time zones, there are more than 24 times zones in the world.
Yet, throughout my career, I've noticed that frequently, organizations fail to effectively communicate meeting and event start times across time zones. Here are a few tips and considerations for communicating time:
Standard vs. Daylight Saving Time
We sometimes take things for granted and forget the reason for the terminology. At the risk of being obvious, let's consider what "standard" time is. Remember that the earth is spinning on its axis and is making a full rotation relative to the sun every 24 hours. That means that every location on the earth is positioned closest to the sun at around noon every day -- regardless of latitude or vertical position on the earth. During "standard" time, that "high noon" time is actually 12:00pm, give or take depending on the position within the timezone. For places that observe Daylight Saving time, the sun is highest at around 1:00pm during Daylight Saving time.
Knowing that, remember that "standard" time refers to the time of the year when you are not observing "daylight saving" time. The word "standard" does not refer to your preferred time or, for my friends on the east coast of the US, not your belief that the world revolves around you. It is not "the standard" time, it's "standard" vs. "daylight saving time".
In the US, Daylight Saving Time (DST) starts on the second Sunday in March of every year and ends on the first Sunday in November. It is observed in all US states except Arizona and Hawaii. The clocks are adjusted at 2:00am local time. When you are not in DST, you are in "standard" time.
Keep in mind that Hawaii and most of Arizona (the exception is the Navajo Nation) do not change time all year, so the relative time difference between those locations and other locations varies by the time of year.
Helpful Tech Tools
Does it all seem too confusing for you? If so, there are many tech tools to find the correct time in various locations, including websites, smartphone apps (see screenshot of customizable iPhone clock app below), shared calendars that convert times for you, etc., but still, in messaging, we must learn to properly convey local times.
Daylight Saving Time
When specifying that an event occurs at a certain time during "Daylight Saving Time", you can use an abbreviation (e.g., in the US, "EDT" refers to Eastern Daylight Time). Never add an "s" to the end of "Saving". It is not plural -- it's not "Daylight Savings" time.
How to use "standard" time
The word "standard" does not refer to one's preferred time and it is not "the standard" time, it's "standard" vs. "daylight saving time". When specifying that an event occurs at a certain time during "Standard Time", you can use an abbreviation (e.g., in the US, "MST" refers to Mountain Standard Time).
Identifying an event time in written communications
If you're sending out an email to a global audience and referencing a specific time, be sure to clearly state the time zone clearly. Don't try and account for every audience member's time zone -- just pick a time zone and let the audience convert to their own time zone using their preferred tool, but be sure to state the time zone clearly.
For those not familiar with your local time zone abbreviation, write it out, or reference the Coordinated Universal Time. (Prior to 1972, it was called Greenwich MeanTime (GMT) but is now referred to as Coordinated Universal Time or Universal Time Coordinated (UTC).)