Dear Mary
Thank you for inviting me to your birthday party. I am touched that you are still thinking of me after all these years after graduation. Our friendship is invincible and cannot be changed no matter what happens. However, I sincerely apologise for being unable to attend this special event because of an important meeting on the day.
This meeting is especially important for me since it determines whether I will be getting a promotion or not and this opportunity is essential as it influences my future career pathways which I cannot be absent from. The meeting is scheduled for 4 hours including 8 mini interviews and one written examination. In the morning before the interview I would have to get all the materials ready and travel to the interview venue with public transport which roughly takes me two hours. Thus it can be overwhelming if I participate in your party in the afternoon.
Once again I feel disappointed and sorry for being unable to attend, I wish you a very happy birthday and hope your party is filled with love and joy.
Kind regards
Jack
