The power of the President to refuse to approve a bill or joint resolution and thus prevent its enactment into law is the veto. The president has ten days (excluding Sundays) to sign a bill passed by Congress. A regular veto occurs when the President returns the legislation to the house in which it originated, usually with a message explaining the rationale for the veto. This veto can be overridden only by a two-thirds vote in both the Senate and the House. If this occurs, the bill becomes law over the President's objections. A pocket veto occurs when Congress adjourns during the ten-day period. The president cannot return the bill to Congress. The president's decision not to sign the legislation is a pocket veto and Congress does not have the opportunity to override.