A few points I find interesting:
- in 2022 a decision was made to abolish leap seconds by 2035, by allowing UTC to drift from the time as defined by Earth's rotation (UT1)
- negative leap seconds, while established, were never actually used
- ice melting caused by climate change has a slowing down effect on rotation of the planet, delaying a need for a negative leap second until 2029, otherwise forecasted in 2026
