OCI: DST Timezone Change is Not Taking Effect on Linux Instances

Applies To:
Oracle Cloud Infrastructure
Oracle Linux

Symptoms:
After the Daylight Saving Time (DST) transition, the system time on OCI Linux instances remains unchanged and continues to display in GMT rather than switching to BST.

[root@<HOSTNAME> ~]# zdump -v Europe/London | grep 2025

Europe/London  Sun Mar 30 00:59:59 2025 UTC = Sun Mar 30 00:59:59 2025 GMT isdst=0 gmtoff=0

Europe/London  Sun Mar 30 01:00:00 2025 UTC = Sun Mar 30 02:00:00 2025 BST isdst=1 gmtoff=3600

Europe/London  Sun Oct 26 00:59:59 2025 UTC = Sun Oct 26 01:59:59 2025 BST isdst=1 gmtoff=3600

Europe/London  Sun Oct 26 01:00:00 2025 UTC = Sun Oct 26 01:00:00 2025 GMT isdst=0 gmtoff=0

[root@<HOSTNAME> ~]#

[root@<HOSTNAME> ~]# date

Mon Mar 31 11:19:35 GMT 2025

[root@<HOSTNAME> ~]#

Cause
The system timezone is configured to a static timezone i.e GMT (+0000) instead of a dynamic timezone (Europe/London) that supports DST transitions.