When buff/debuff timer is above the threshold set in ElvUI Config, it will display buffs as HH:MM:SS format instead of "1h" or "10m". Days display as DD:HH:MM with a "d" to note that it is days. Ex: 5d:13:02 is 5 days, 13 hours, 2 minutes remaining. This is mostly due to the contract buff duration.
Font is changed through ElvUI.
8.1.2 - When a buff lasts for a day or longer the format will change instead of showing hours over 24.