How to calculate Mandays for half-yearly return under the Factories Act?

Dear Sir/Madam,

Please help me. How do I calculate Mandays under the Factories Act? In my company, we engage 150 contract laborers and 300 company workers every day. However, the daily attendance varies, with contract workers ranging from 145 to 130, and company workers ranging from 290 to 280. How can I calculate Mandays for the half-yearly return (January to June) when attendance fluctuates daily? Your assistance would be greatly appreciated. Thank you.

Dear ABC,

First of all, do not hide your identity. It may be difficult for us to understand why you are hesitant to use your own name.

Secondly, for the man-days calculation, calculate the average number of men for each month and do the same for a six-month period.

To know about man-days calculation and man-hours calculation for annual returns, in my factory, there are 500-600 employees working every month.

Please let me know the formulas and methods to calculate these metrics accurately. Thank you for your assistance.