If your divorce covenant does not make any mention of the division of your pension, the standard legal rules will apply: ‘pension equalisation’. The old-age pension that you accrued during your marriage is divided exactly 50-50 under the standard rules. Your ex will receive that equalised pension from the date of your retirement.
You may deviate from this rule and make different arrangements for this in your divorce covenant. For instance, you could agree to waive the right of getting each other's pension or to split your pensions by way of conversion. If you opt for conversion, both of your old-age pensions are split, but your ex-partner gets the converted pension as his/her own pension entitlement. That means your ex-partner is not dependent on your decision to start your retirement. He/she can choose the starting date of the converted pension at his/her own discretion. If you opted for equalisation, your ex-partner will not get that equalised old-age pension until you start your retirement.