where did you check your balance? check it in myetherwallet itself, sites like ethplorer.io and etherscan.io update balances after claiming stakes for ages. as for MEW it shows correct balance in a several minutes after minting which had to be succesful in your case as soon as calculator says it's 0 days of coinage.
Ho you're right ! I was only checking Ethplorer but I see it on MEW, thank you very much for your help, I won't do the same mistake.
How is the POS calculated ? I know that it is between 3 and 90 days holding but each day gives the same % ? How can we calculate it ourself ?
you are very welcome. here is very cool article which compares profit from different methods of minting including difference of starting stake sizes and gas prices https://steemit.com/cryptocurrency/@mvillar/the-last-guide-to-optimal-postoken-mining