Before and after show the boundary labels at the exact UTC transition. A missing or repeated local label still requires an explicit choice in the planner.
Why an identifier matters
An offset describes one moment. A named zone carries the date-specific rules used to calculate each meeting.
Planning dates run from Thu, Jan 1, 2026 through Mon, Dec 31, 2035. Future rules can be revised; review the data version when a distant schedule matters.
America/Chicago uses UTC−06:00 in the January sample and UTC−05:00 in July. A label such as CST is not a safe worldwide identifier: abbreviations can be reused by unrelated zones. Choose this IANA name when the intended local clock is Chicago’s.
Offsets in the bundled rules
Sampled at 12:00 UTC on each date, using IANA 2026f.
Date
UTC offset
Display abbreviation
2026-01-15
UTC−06:00
CST
2026-07-15
UTC−05:00
CDT
2026-10-27
UTC−05:00
CDT
2026-11-03
UTC−06:00
CST
Resolve the wall time before exporting
The local time 02:30 on 8 March 2026 is missing in this zone. On 1 November, 01:30 repeats at UTC−05:00 and UTC−06:00. A recurring meeting near these hours needs per-occurrence review, even when most weeks look routine.
Use this identifier in a plan
Find America/Chicago in the zone directory or choose Chicago from the city directory. Add the other meeting locations, enter their availability, and check the complete duration. The supported planning years are 2026–2035; future political rule changes may require a new data version.
A calendar export uses the resolved UTC start and end times. The zone remains part of the planning context, while the exported instant stays unambiguous when another calendar displays it in its own time zone.