Why "First Year AL Entitlement round up to integer"?

According to the Concise guide to the employment ordinance Hong Kong, Chapter 4,  if an employee has not been employed for 12 months in the common leave year, the employer should calculate his leave entitlement on a pro-rata basis, and any fraction of a day resulting from the calculation should be counted as a full day's leave.

You can uncheck the First Year AL Entitlement round up to integer (for Calendar Year Entitlement) check box in Leave Module Setup to disable this behaviour. 

What is the effect when the  First Year AL Entitlement round up to integer (for Calendar Year Entitlement)  is turned on? 

Assume 10 days per year (C – In Advance)

An Employee joins the company in the middle of the year. 

As of 2019/12/31 (End of First Leave Year)

For Eligible Entitlement, 

9 days Eligible Entitlement is calculated from 

Days between 2019/03/06 to 2019/12/31 is 301          

10 days x 301 / 365 = 8.25 days 

When First Year annual leave entitlement round up to integer is turned on, it becomes 9 days (The first year round-up difference 0.75 days is added to the entitlement).

For Actual Entitlement, 

Actual Entitlement is accumulated day by day, each day 10/365 days. 

So at the end of the leave year it becomes 10 x 301 / 365 = 8.24657534, round to 2 decimal place become 8.25. 

As of 2020/01/01 (Start of Next Leave Year),

Please note that the Brought Forward of “Current Year (Actual)” included the value of the First Year Round Up Difference(i.e. 0.75 days). The 0.75 days are added across the first leave year and included in BF.