Is an employee entitled to end of service benefits if he voluntarily resigns?

Hi!

I hope someone can help with my query.

I have an employee who was seconded to work in Qatar from HQ in Singapore. He was working in Qatar as an expatriate since 2005 but only in 2009 did he have a local contract in Qatar. The secondment contract from Singapore is renewed every 2 years. However, the local contract in Qatar is an indefinite one.

His basic pay is paid in Singapore, only allowances are being paid in Qatar.

He has voluntarily resigned recently.
1.Will he be entitled to the 21 days per year of service payment upon resignation?

If he is entitled to the end of service benefit payment,

2.I understand that the payment is computed using basic pay. However, as mentioned above, only his allowances are being paid in Qatar. How would this affect the computation?

3.Legally, is it acceptable to compute his end of service payment from year 2009 where he starts to have a local contract in Qatar?

Thank you for reading and I hope I can get some advice soon.

Regards
VT