How long does the beginners cash boost last?

I think it was explained during joining, but I can't remember.

There's currently a monthly boost of 26B and an occasional cash boost of 300B. Do they both expire at the same time? And when?

I'm running a profit of about 20 million, so obviously I would be put in the reds if the boost was to stop any time soon.

If I remember correctly (keep in mind is has been years) the boost gets smaller and smaller untill it dissapears. It shouldn't drop from 26B to zero overnight.

I think the documentation says it lasts up to 80 days, or until you have received 4T & 4.5M pop.