- update to 2022.7:
* In the Mexican state of Chihuahua, the border strip near the US
will change to agree with nearby US locations on 2022-11-30.
The strip's western part, represented by Ciudad Juárez, switches
from -06 all year to -07/-06 with US DST rules, like El Paso, TX.
The eastern part, represented by Ojinaga, will observe US DST next
year, like Presidio, TX.
A new Zone America/Ciudad_Juarez splits from America/Ojinaga.
* Much of Greenland, represented by America/Nuuk, stops observing
winter time after March 2023, so its daylight saving time becomes
standard time.
* Changes for pre-1996 northern Canada
* Update to past DST transition in Colombia (1993), Singapore
(1981)