The relevant date is rarely the date of divorce
About the relevant time, this will depend on the particular provincial statute. In British Columbia, the relevant time for identifying family property is the date of separation, not the date of divorce. See the Family Law Act, s. 84. In Ontario, the relevant date is the earliest of 1) the date of separation; 2) the date of divorce; 3) the date the marriage is declared a nullity; and a couple of other rare circumstances. See the Ontario Family Law Act, s. 4(1). In Saskatchewan, the relevant date is "the time an application is made pursuant to this Act." See Saskatchewan's Family Property Act, s. 2.
Property or value acquired after separation is only counted where it is "derived from" property that was owned by one of the spouses at the time of separation (or whatever the relevant date is in the province).
In summary, you would identify what is family property on whatever the relevant date is in the couple's province. Then you would also include any property acquired after that date if it was "derived from" the property owned on the relevant date. So, post-separation income would not become part of family property (Phillips v Saunders, 2018 BCSC 960 at para. 71. But a post-separation home acquired using equity from the family residence does become part of family property (K.P.B. v. K.E., 2019 BCCA 152).
Some additional clarifications
It is an oversimplification to say that "wives get 50% of net worth". The only sense in which that statement is correct is in that in every province, there is a presumption that there will be an equal division of what is considered family property (or in Quebec, family patrimony).
But what is included for the presumptive 50/50 division is not the entirety of the couple's net worth. The starting point is usually that all real and personal property owned on the relavant date (separation, divorce, application) is family property, including bank accounts, shares, "an interest in a partnership, an association, an organization, a business or a venture," (language taken from B.C.'s Family Property Act), real property, entitlements to retirement plans, etc. Some provinces also direct that debt also be divided equally (BC and Ontario, for example). Others do not (e.g. Saskatchewan, although debt is a factor that can be considered by a judge in deciding whether to deviate from an equal division of the family property). To determine what is family property, you must read the relevant statute in your jurisdiction.
Many things are then excluded from division, though: typically, property owned prior to the marriage by either party is excluded, settlements or awards from lawsuits, and inheritances. The family home is also sometimes treated specially, where sometimes its value is included for property division even if it were to fall within one of the normally excluded categories. See this other answer about division of the family residence in various provinces in Canada..
Second, property division is not specific to wives. Property division regimes apply to any couple who have become spouses. In all provinces except Quebec, this can happen through cohabitation in a marriage-like relationship.