Drinking a potion will add to the duration of an active effect.
Toggle stacking potion durations with /gamerule potiontimestacker:stack_potions (default true)
Toggle stacking splash potion durations with /gamerule potiontimestacker:stack_splash_potions (default false)
Modify maximum effect duration with /gamerule potiontimestacker:max_effect_ticks (default uncapped) (1 second = 20 ticks)
Whitelist or blacklist potions by editing the config file in config/potiontimestacker.toml
The Potion Time Stacker Team
