Good morning from New Zealand - currently in NZDT timezone -13:00 as at 3am this morning.

Summary version - looks like there may have been a change some time in the past 12 months that impacted either the sql version check, or the timezone checks.
No issues 12 months ago - but woke up this morning to 600 odd emails reporting:
PHP Fatal error: Uncaught Exception: SQLSTATE[HY000]: General error: 1298 Unknown or incorrect time zone: '-13:00' in /usr/bin/greyhole:730 Stack trace: #0 /usr/bin/greyhole(705): DB::execute('SET time_zone =...', Array) #1 /usr/bin/greyhole(8409): DB::connect(false) #2 /usr/bin/greyhole(8367): CommandLineHelper->getRunner() #3 /usr/bin/greyhole(8628): CommandLineHelper->processCommandLine() #4 {main} thrown in /usr/bin/greyhole on line 730

Identified cause - Ubuntu 18.04 LTS only bundled up to mysql-server-5.7 - timezone -13:00 was not supported until 8.0.13
Refer: https://dev.mysql.com/doc/refman/8.0/en/time-zone-support.html#time-zone-variables
greyhole is still attempting to set timezone -13:00 and repeatedly raising an error each time it fails

Workaround - add the mysql apt repo and upgrade to mysql-server-8
Official instructions at: https://dev.mysql.com/doc/mysql-apt-repo-quick-guide/en/#repo-qg-apt-upgrading
Example (shorter) read at: https://www.digitalocean.com/community/questions/upgrade-mysql-5-7-to-8-ubuntu-18-04?comment=153968
For my purposes I've retained legacy (5.7.x) authentication support when prompted during upgrading, and appears to have resolved the issue with greyhole no longer throwing an error.

Thx.