Depending on the relationship with the person retiring, would determine what to say in a written Happy Retirement. If the relationship is not a close on, a simple "Congratulations and Happy Retirement" would be sufficient.
"Maligayang pagreretiro" is how you say happy retirement in Tagalog.
In Flemish, you can say "Gelukkige pensioen" to wish someone a happy retirement.
In Afrikaans, you can say "gelukkige aftrede" to wish someone a happy retirement.
Happy retirement! translates as Alles Gute für den Ruhestand.
If you want to say happy retirement in Italian you would say, pensione felice. You would say good luck by saying buona fortuna.
Feliz jubilación! or simply "Felicidades!"
To say "happy retirement" in Irish Gaelic, you can say "Go n-éirí an bóthar leat" which translates to "May the road rise with you." Another option is "Aoibhinn conradh scoir," meaning "happy retirement." These phrases convey well wishes for a joyful and fulfilling retirement.
Je vous souhaite de passer une bonne et heureuse retraite.
Feliz aposentadoria.
In finnish: hyvää eläkettä
Irving Salomon has written: 'Retire and be happy' -- subject(s): Retirement
In Korean, you can say "행복한 은퇴를 기원합니다" (haengbokhan euntwae-reul giwonhamnida) to wish someone a happy retirement. Another common expression is "은퇴를 축하합니다" (euntwae-reul chukhahamnida), which means "Congratulations on your retirement." Both phrases convey warm wishes for a joyful retirement.