https://thenextweb.com/syndication/2019/08/25/plant-cells-signal-between-each-other-to-agree-on-what-time-it-is/

Anyone who has travelled across multiple time zones and suffered jet lag will understand just how powerful our biological clocks are. In fact, every cell in the human body has its own molecular clock, which is capable of generating a daily rise and fall in the number of many proteins the body produces over a 24-hour cycle. The brain contains a master clock that keeps the rest of the body in sync, using light signals from the eyes to keep in time with environment.

Plants have similar circadian rhythms that help them tell the time of day, preparing plants for photosynthesis prior to dawn, turning on heat-protection mechanisms before the hottest part of the day, and producing nectar when pollinators are most likely to visit. And just like in humans, every cell in the plant appears to have its own clock.