The Kremlin clock on the Spasskaya (Savior) Tower, in halls and offices will be adjusted for the energy-saving (summer) time.
Specialists will ascend the Spasskaya Tower to manually adjust the Kremlin chimes, Russia's main clock, spokesman for the Federal Protection Service Sergei Devyatov told RIA Novosti.
"The Kremlin chimes are not digital but genuine weight clock, so they should be adjusted manually," he said.
According to Mr. Devyatov, the rarity is treated with great care so the adjustment does not influence its accuracy and mechanism.
Russia's main clock is in normal working condition, which is maintained by permanent technical service," he noted.
The chimes and other unique clocks of the Grand Kremlin Palace will be adjusted manually as well, Sergei Devyatov added.
The clocks in Kremlin offices will be put forward, too, he said.
The first clock appeared by the Frolovskiye (Savior) Gates in 1614. The new clock designed by Englishman Christopher Halloway replaced it in 1624. A pavilion was built for it. Russian craftsmen cast 13 bells for the chimes.
Peter the Great was the first to order a clock in the German style, with a face having 12 points instead of 24.
The clock was made in Holland and assembled on the Spasskaya Tower in 1706-1709. The clock chimed at midday and midnight.
The clock was damaged during Napoleon's invasion. It was restored in 1815.
During the October revolution of 1917 the clock was damaged again. It was repaired and started playing "The International" and a revolutionary song "You Fell Victim".
In the 1930s the Kremlin clock chimed to mark each hour and quarter.
In 1995 the chimes started playing "The Patriotic Song" and "Glory!" by Russian composer Mikhail Glinka (1804-1857).
Five years ago, the four clock-faces, eight hands and 48 figures of the chimes underwent an X-ray examination, were grounded and gilded. This work was done inside the Spasskaya Tower. After that, the faces and hands were put back, the mechanism was adjusted and launched.
The clock's musical mechanism was restored as well. Three more tunes were added to it.