Signing bonus that you only after x months of work, is this normal?

You should insist that the "pay it back to them":

1. only applies if you quit, not if they fire you

2. be pro-rata -- i.e. if you quit after 9 months, you only pay back (12-9)/12 = 1/4 of the bonus

With the above, you can also ask (not necessarily insist), that they pay you the bonus now, or by the next paycheck.

This is very common as some companies don't want to you disappear within 3 months of joining because they have spent a lot of money hiring you.

The year part of it is to make sure that they have "made back" their signing bonus.

Yes, that's not unusual.

Were you really planning on taking the signing bonus, and jumping in less than a year?