Caution on upgrading park hoppers to annual pass

I recentlypurchased some park hopper passes with family members. We decided to upgrade at the end of our visit. When my niece went to purchase her annual pass they grilled her on how the park hopper ticket had been used. Questions included when did first use the park hopper? Which park did you visit first ? What time of day did you enter the park ? It would be smart to make a record on every useof each park hopper ticket to insure that you can upgrade if you wish.