TOST — Tonga Summer Time
See what TOST means, when UTC+14 applies in Tonga, and convert it accurately to other time zones.
Meaning and usage
TOST stands for Tonga Summer Time and uses a UTC+14 offset. It is the daylight saving time designation used in Tonga when DST is in effect.
DST relationship explained
TOST is the summer-time variant for Tonga and applies only during daylight saving periods. This page helps distinguish it from Tonga’s standard time and shows when the DST offset is active.
Convert other time zones
Compare TOST with other zones using the visual time grid and hour-by-hour tables. Export meetings with ICS download or send to Google Calendar and Gmail with automatic timezone handling.
How to Convert TOST to Other Time Zones
Open the TOST converter page: Go to https://www.xconvert.com/time-converter/tost-time-zone to open the comparison grid with TOST — Tonga Summer Time already loaded. This view is useful when you need to line up work hours visually for international coordination, especially because TOST is UTC+14, placing it at the far-ahead end of the global day.
Add comparison cities or time zones: Click + Add City and search for the places you want to compare against TOST. A practical setup is to add the cities where your clients, suppliers, or remote teammates work so you can see how a TOST business window overlaps with their local schedules on the same 24-hour timeline.
Select a meeting window on the grid: Click Select, then drag across the colored timeline in the TOST row to highlight a time range in purple; use the side handles to fine-tune the start and end, or drag the center to move the whole block. This is especially helpful for planning calls, travel coordination, or handoffs because you can compare a TOST morning, afternoon, or evening block against every added row without typing times manually.
Export and share the result: Once a range is selected, use the export options for ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link. That makes it easy to send a confirmed time window to a distributed team, attach it to a calendar invite, or share a link with partners so everyone sees the timing in their own local context.
About Tonga Summer Time (TOST)
TOST stands for Tonga Summer Time. Its exact offset is UTC+14, which places it among the earliest time zones in the world relative to Coordinated Universal Time.
TOST is a daylight saving time abbreviation rather than a standard-time abbreviation. A same-offset abbreviation is LINT, which also uses UTC+14, although abbreviations with the same offset are not necessarily interchangeable in regional usage.
Tonga Summer Time is identified here by its abbreviation and offset relationship rather than by a list of cities. For time conversion, the key operational detail is that any schedule marked in TOST should be interpreted as 14 hours ahead of UTC.
TOST and Daylight Saving Time
TOST is specifically a daylight saving time abbreviation. That means it represents a summer-season clock setting rather than a year-round standard designation.
A standard counterpart is not listed here, so there is no alternate abbreviation to describe in this reference. Exact switch dates for the current year are also not included here, so the most reliable fixed detail for planning is that TOST itself means UTC+14 during the daylight saving period.
When you see TOST on a schedule, calendar, or time conversion page, the important point is that the time is already expressed in the daylight-saving version of the zone. For business coordination, that distinction matters because a meeting labeled TOST should be treated as UTC+14, not as a generic Tonga time label.
Frequently Asked Questions
What does TOST stand for?
TOST stands for Tonga Summer Time. It is the daylight saving abbreviation associated with Tonga’s summer clock setting and uses an offset of UTC+14.
Is TOST the same as GMT?
No. TOST is UTC+14, while GMT refers to the zero-offset baseline used at UTC+0. That means TOST is 14 hours ahead of GMT, so a time written in TOST is far ahead of the Greenwich reference used in many international schedules.
Which cities use TOST?
A city list is not part of this reference entry, so TOST is best identified by its abbreviation and offset rather than by named urban locations. For conversion purposes, the actionable detail is that any time marked TOST should be read as UTC+14.
What is the UTC offset for TOST?
The UTC offset for TOST is UTC+14. This means you add 14 hours to UTC to interpret a TOST timestamp correctly in international planning, scheduling, and calendar coordination.
Is TOST a daylight saving time abbreviation?
Yes. TOST is a daylight saving time abbreviation, not a standard-time abbreviation. That is why it is described as Tonga Summer Time, with “Summer Time” indicating the DST period rather than a permanent year-round setting.
What does TOST switch to when daylight saving ends?
A standard counterpart is not specified here. The key practical point is that TOST itself refers to the daylight saving version of the time zone, so if you see TOST on a calendar or project schedule, you should interpret it using UTC+14.
When does TOST change?
Exact daylight saving transition dates for the current year are not included in this reference. What remains constant for conversion is that whenever TOST is in effect, it represents UTC+14.
Is TOST the same as LINT?
They share the same offset, but they are not the same abbreviation. TOST and LINT are both UTC+14 abbreviations, so they align numerically on a clock conversion, but abbreviation choice depends on the specific regional time-zone label being used.