NEW YORK (Reuters) - The U.S. Treasury said on Friday it is seeking guidance from primary dealers on stablecoins as well as potential changes to the 20-year bond auction schedule, including possibly shortening the when-issued period.

The when-issued period typically begins after the announcement of a new security issue and ends the day before the actual issuance date. Trading typically occurs during this period, allowing investors to participate in the market and express their view on the price of the security.

Meetings by the U.S. Treasury with primary dealers will be on April 24 and 25, with their input on budget deficit and debt issuance estimates, among other topics, to be considered for the refunding announcement in May. Primary dealers are trading counterparties of the New York Federal Reserve, acting as market makers on U.S. government debt.

The 20-year auction is currently announced mid-month, settled at the end of the month, and has a mid-month "dated date", the period in which interest starts or accrues on a bond.

The "dated date" is important for calculating accrued interest, especially when a bond is sold between interest payment dates.

This schedule often results in a longer when-issued period for 20-year bond sales, including auctions of the Treasury Inflation-Protected Securities, compared to other auctions, the documents showed.

The department also sought comments from dealers on the potential demand for Treasury securities as a reserve asset for stablecoins, particularly given recent Congressional action in this area.

Stablecoins, a type of cryptocurrency designed to maintain a constant value, usually a 1:1 dollar peg, are commonly used by crypto traders to move funds between tokens. Their use has grown rapidly in recent years, and proponents say that they could be used to send payments instantly.

The House of Representatives and the Senate have both introduced bills to create a regulatory regime for stablecoins. The Senate Banking Committee advanced one measure last month, and the House Financial Services Committee approved another last week.

(Reporting by Gertrude Chavez-Dreyfuss in New York; Editing by Nia Williams)