Event-Time-Zone-Implementation-Planning.md

@@ -4,8 +4,8 @@
 
 * __Time Zone__: The *time zone* is a social/political/geographical construct; within some geographic zone, there is a shared norm for tracking time.
     * (_Ex: "The adjacent states of Iowa, Missouri, and Illinois follow the exact same rules for tracking time. They are in the same `US/Central` timezone."_)
-* __Time Offset__: The *time offset* is a numerical value (eg `+0400` or `-0200`). To convert between timezones, you need to identify the relevant offsets.
-    * (_Ex: "During winter 2020, the `US/Central` timezone uses an offset `-0600`; during summer 2020, it uses `-0500`."_)
+* __Time Offset__: The *time offset* is a numerical value (eg `+0400` or `-0200`). To convert between timezones, you should identify the relevant offsets. Timezones and offsets correlate _imperfectly_ (eg due to _daylight savings time_ or _new laws_).
+    * (_Ex: "Under the laws of 2021, the `US/Central` timezone uses an offset `-0600` during winter; during summer, it uses `-0500`."_)
 * __Time Perspective__: Dates and times are subjective; the same date/time can present with different values depending on one's timezone. While there are many possible perspectives on an `Event`, we define three key perspectives:
     * The __nominal__ date/time perspective would appear on a printed pamphlet when advertising an `Event`. This is expressed in the *event-specific timezone*.
     * The __canonical__ date/time perspective would drive automated processing (notifications, sorting, etc) on a shared/central server. This is expressed in a *universal timezone* (eg UTC/GMT).