When did Olenna put the poison in Joffrey's Cup?

Related questions

1. How did they get the poison in Joffrey's Cup?
2. How did Olenna die?
3. Who killed Doran Martell?
4. Why did Olenna poison Joffrey?
5. How does margaery die?
6. Is Tyrion Tywin's son?
7. Does Sansa marry Ramsay?
8. How did baratheon die?
9. Who fathered Gilly's child?
10. What happens to Sansa after Joffrey died?

Tags

1. #tyrell
2. #dontos
3. #asked
4. #necklace
5. #necklaces
6. #presumably
7. #reach
8. #joffrey
9. #within
10. #happens
11. #those
12. #sansa
13. #women
14. #poison
15. #poisoned
16. #crystal
17. #poisoning