Why are US flags being flown at half-staff on Inauguration Day? [Video]

President-elect Donald Trump has expressed frustration that flags will be flying at half-staff when he takes office later this month.Related video above: U.S. leaders react to death of former President Jimmy CarterIt’s an action put in place by President Joe Biden to honor the late President Jimmy Carter, who died Dec. 29 at 100. It’s not a timeline that Trump can do anything about — until after he takes office.Here’s what to know about why flags are lowered when a president dies, who can issue that order and how long the process lasts:Why are US flags being flown at half-staff?On Sunday, Biden ordered that U.S. flags be flown at half-staff in honor of the late former president. It’s an honor that indicates that the country or a state is in mourning.The U.S. flag code lays out parameters for lowering the U.S. flag to half-staff, including a 30-day period for current …