As I see it, accrual is not being used in financial way. It relates to the number of holiday days you are entitled to. If for example 24 days a year is the normal holiday entitlement, then, after your first year you can take 24 days whenever you like divided up however you like if your employer agrees. During you first year you only get 1/12 of 24 days i.e. 2 days for every month you have worked so at the end of 3 months you could take 6 days holiday (1/4 of 24).

The word "accrual" is most often used in accounting and finance, which is what the dictionary assumes. I suggest you Google the verb "to accrue". From Google: (a) (of a benefit or sum of money) be received by someone in regular or increasing amounts over time. e.g. "financial benefits will accrue from restructuring" (b) accumulate or receive (payments or benefits) over time. e.g. "they accrue entitlements to holiday pay" So as a noun, "accrual" is the THING accrued. In your example, holiday. In accounting, some kind of expense (such as interest). Hope this helps

That's a case of the dictionary giving the definition in a financial context, not a general one. To accrue is just to get more of something over time.