September 6, 2015 - Serena Williams in action in a women's singles fourth-round match against Madison Keys during the 2015 US Open at the USTA Billie Jean King National Tennis Center in Flushing, NY. (USTA/Andrew Ong)

Impending rains Thursday night have altered the 2015 US Open schedule.

The women’s semifinals, originally scheduled for Thursday evening (session 21), will now be played as a single session starting at 11 a.m. ET on Friday. Gates will open at 10 a.m. ET.

The men’s semifinals (session 22) will now have a start time of 5 p.m. Session 22 ticketholders will have access to the grounds beginning at 10 a.m. and entry to Arthur Ashe Stadium following the women’s semifinals.

Simona Halep and Flavia Pennetta, both bidding for their first US Open women’s singles final, lead off the day’s play at 11 a.m., followed immediately afterward by Serena Williams and Roberta Vinci. Serena is two victories away from capturing the first calendar-year Grand Slam since Steffi Graf in 1988.

The men’s semifinals feature 2011 US Open winner Novak Djokovic facing defending champion Marin Cilic leading off, followed by five-time champion Roger Federer against reigning French Open champion Stanislas Wawrinka.

Fuertes lluvias en Nueva York obligaron a reprogramar las semifinales femeninas que debian jugarse hoy jueves…y debieron programarse para el viernes desde las 11 AM…

Las semifinales masculinas comenzaran a las 5 de la tarde, seguidas de las semifinales femeninas..

Simona Halep y Flavia Pennetta las dos buscando su primera final en el US Open, iniciaran la jornada a las 11AM, seguida inmediatamente del partido entre Serena Williams y Roberta Vinci. Serena esta a dos victorias de lograr el poker de Grand Slam en la misma temporada, por primera vez desde que lo consiguiera SteFfe Graf en 1988…

Las semifinales masculinas enfrentaran a Novak Djokovic y Marin Cilic a primera hora y de fondo Roger Federer contra Stanislas Wawrinka….