When is Shrove Tuesday (Pancake Day)?

1To the chief Musician, A Psalm of David, when Nathan the prophet came unto him, after he had gone in to Bath–sheba. Have mercy upon me, O God, according to thy lovingkindness: according unto the multitude of thy tender mercies blot out my transgressions. 2Wash me throughly from mine iniquity, and cleanse me from my sin. 3For I acknowledge my transgressions: and my sin is ever before me. 4Against thee, thee only, have I sinned, and done this evil in thy sight: that thou mightest be justified when thou speakest, and be clear when thou judgest. 5Behold, I was shapen in iniquity; and in sin did my mother conceive me. 6Behold, thou desirest truth in the inward parts: and in the hidden part thou shalt make me to know wisdom. 7Purge me with hyssop, and I shall be clean: wash me, and I shall be whiter than snow. 8Make me to hear joy and gladness; that the bones which thou hast broken may rejoice. 9Hide thy face from my sins, and blot out all mine iniquities. 10Create in me a clean heart, O God; and renew a right spirit within me. 11Cast me not away from thy presence; and take not thy holy spirit from me. 12Restore unto me the joy of thy salvation; and uphold me with thy free spirit.