Under the occupational pension plan, the obligation to make contributions ceases as of the date of regular retirement. The deduction for BVG/PK cannot be waived, even in the case of early retirement. AHV contributions, including those for non-working individuals, must also be paid until the statutory retirement age. It does not matter whether the old-age pension was taken early or not.
If individuals remain employed beyond the normal retirement age, they are still required to pay contributions but benefit from an exemption (see section 14 et seq. https://www.ahv-iv.ch/p/2.01.d).
The normal retirement age is 65 for men and 64 for women.