Hay formally issued his Open Door note on September 6, 1899. This was not a treaty, and did not require the approval of the Senate. Most of the powers had at least some caveats, and negotiations continued through the remainder of the year. On March 20, 1900, Hay announced that all powers had agreed, and he was not contradicted. Former secretary Day wrote to Hay, congratulating him, "moving at the right time and in the right manner, you have secured a diplomatic triumph in the 'open door' in China of the first importance to your country".