To all programmers here, the TZ=:<zonefile> syntax is currently unsupported in the icu library (International Components for Unicode): https://unicode-org.atla

To all programmers here, the TZ=:<zonefile> syntax is currently unsupported in the icu library (International Components for Unicode): https://unicode-org.atlassian.net/browse/ICU-13694 https://unicode-org.atlassian.net/browse/ICU-13694 https://github.com/unicode-org/icu/pull/2213 https://github.com/unicode-org/icu/pull/2213 This affects all packages that have icu as a dependency, one of them being Node.js. https://github.com/nodejs/node/issues/37271 https://github.com/nodejs/node/issues/37271 I discovered this the hard way when some code malfunctioned shortly after daylight savings time kicked in.