If you have the R09 Calbe (old Rodinal) it can be finished within 2 years.
Robert, please don´t discredit the R09´s longevity
I use R09 from 1989! and it still works. Maybe the times differ from the from the producer original intended, but I´m not even sure about that since I have no comparison with dilutions about 1:150. The R09 I use is open and half full since two years. No blank film ever, it simply works.
@MarcoGiardini
One should think there was no Rodinal in the tank during development, maybe it was pure water or maybe it was fixer, because the film is totally blank. But you said, you directly mixed the Rodinal and stored it a few minutes, before filling it into the development tank with the film. Make an easy test: Mix a small amount of Rodinal 1+25 and try to develop an exposed snipped from the start of any b/w film. If it don´t blackens after 3 minutes then your Rodinal is and was surely dead. If not, then you have the seldom case of a production mistake at the Ilford´s
Don´t care too much about your mistake - it makes you more watchful in the future. And by the way after years without any bigger fault, I recently heavily underdeveloped a film because I weighed one of the raw chemicals for the developer wrongly. Since one week I try to save the negatives by many different chemical ways of manipulating them...
Better luck for the future,
Andreas