DST start and end dates keep changing over the years for different timezones. For example, I found below link where DST start and end dates are provided for EST for different years. https://www.timeanddate.com/time/zone/usa/new-york?year=1963 In Windows, we can update a timezone info using the registries. In SUSE linux, we get updated timezone file updates and steps to apply the updates are given in the below link: https://www.suse.com/support/kb/doc/?id=000016358#:~:text=Linux%20will%20change%20to%20and,DST%20is%20entered%20or%20left. However, I couldn't find a way to update the timezone for DST changes in RHEL and Oracle Linux. I need help regarding this.

1 Answer 1


The start and end dates keep changing, but in many cases the rules that define them don’t; for example, EST switches to EDT at 2am on the second Sunday in March since 2007. The time zone database used on Linux systems (and others) encodes the rules, not the dates, whenever the dates can be calculated.

For time zone rules which do change, or time zones with specific dates, keeping your systems updated will ensure that your systems are aware of the changes. This will also take care of leap seconds. On RHEL and Oracle Linux, make sure the tzdata package is kept up-to-date. The instructions you found for SUSE are the manual equivalent of updating the tzdata package; they will work on RHEL and Oracle Linux too.

  • It is possible the OP needs to update the DST information for some location that decides the DST times separately for each year (yes, those exist!) and/or has the misfortune of needing to maintain old systems that have already dropped out of official support (I've been in that position a few times). The SUSE instructions for manual updates are not specific to SUSE, but applicable to most distributions, including RHEL and Oracle Linux.
    – telcoM
    Apr 17, 2023 at 6:20
  • Right, the last part is what the last sentence of my answer was supposed to convey. For locations which change DST dates every year, there are tzdata updates pretty much as soon as the rules are published, but it can happen that the distro updates aren’t ready on time... Apr 17, 2023 at 6:48

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