The New Testament gives several accounts of Jesus being anointed in the days prior to His death and Resurrection. John places an anointing six days before the Passover (see John 12:2–8) while Matthew and Mark place the event two days before (see Matthew 26:6–13 and Mark 14:3–9). There are similarities in the accounts but also distinct differences.
I have always thought they were two accounts of the same event, but this video opened my eyes. I am now reconsidering my assumptions. Always a healthy thing.