In brief: It’s all too difficult.

There’s no leap second this year, and the BIPM abolishes the practice as of 2027-05-20.

The General Conference on Weights and Measures (CGPM), at its 28th meeting, […]

noting that […] the use of different mitigation methods for leap second introductions by global service providers in their server systems, in order to avoid time steps, leads to inconsistency in timing between different systems and in the disseminated time and frequency, which do not conform to the SI unit, […]

decides that […] continuous UTC will become effective on 20 May 2027,

the maximum value for the difference |UT1-UTC| will be 3 600 seconds (1 hour), ensuring the long term continuity for UTC for several centuries, […]