If a user's birthday/work anniversary is missed due to any issue (formatting, etc) or you are wanting to backdate user's points from before you had Nectar, here is the best way to do it!
You will want to create a Custom Award with the subject of the points and the same point value you have in your automation.
Then you will send the Custom Award through the Awards tab to the users on your Home screen!
For work anniversaries, if you are wanting to do different point amounts for milestone years, you could either create a separate custom award for each point value, or just create one custom award for Work Anniversary, and go back and edit the points for each value.
Feel free to chat with support (red bubble in the bottom right corner of your Nectar account) for any further questions!