How many days does the President have to sign a bill

10

Explanation:

The Constitution provides the President 10 days (excluding Sundays) to act on legislation or the legislation automatically becomes law. There are two types of vetoes: the “regular veto” and the “pocket veto.” The regular veto is a qualified negative 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.

Normally if a president does not sign a bill, it becomes law after ten days as if he had signed it. ... If Congress prevents the bill's return by adjourning during the 10-day period, and the president does not sign the bill, a "pocket veto" occurs and the bill does not become law.

                                                            The president can approve the bill and sign it into law or not approve (veto) a bill. If the president chooses to veto a bill, in most cases Congress can vote to override that veto and the bill becomes a law. But, if the president pocket vetoes a bill after Congress has adjourned, the veto cannot be overridden.

Explanation:

The Constitution provides the President 10 days (excluding Sundays) to act on legislation or the legislation automatically becomes law. There are two types of vetoes: the “regular veto” and the “pocket veto.” The regular veto is a qualified negative veto.