The pips are available to BBC radio stations every 15 minutes but except in rare cases, they are only broadcast on the hour, usually before news bulletins or news programmes. Normally, BBC Radio 4 broadcast the pips every hour except at 18:00 and 00:00 and at 22:00 on Sundays (at the start of the Westminster Hour) when they were replaced by the Westminster chimes of Big Ben at the Palace of Westminster. However, the chimes have been suspended temporarily for the duration of the refurbishment of the clock mechanism. No time signal is broadcast at 15:00 on Saturdays and at 10:00 and 11:00 on Sundays. This is caused by the scheduling of the afternoon play on Saturday and the omnibus edition of "The Archers" on Sunday. On BBC Radio 2, the pips are used at 07:00, 08:00 and 17:00 on weekdays, at 07:00 and 08:00 on Saturdays and at 08:00 and 09:00 on Sundays.