Night Shift Allowance Practice

What is the standard for the payment of night shift allowance – how do companies pay for part of hours worked? Do they pro-rate by the minute or do they round up or down to the nearest hour or half or quarter hour?

Common market practice to entitle for Night Shift Allowance is not based on the pro-ration, but based on the number of minimum hours work required. For example, you need to work for at least 3 hours and more after 12am to be entitled to night shift allowance.