Conservation law, also called law of conservation, in physics, several principles that state that certain physical properties (i.e., measurable quantities) do not change in the course of time within an isolated physical system. In classical physics, laws of this type govern energy, momentum, angular momentum, mass, and electric charge.
On New Yearâs Eve, the Metrorail system will open at 7 a.m. with special extended service on all lines until 3 a.m. The additional three hours of service â consistent with past years â is a special exception to a moratorium on extended hours during the year-long SafeTrack maintenance program.
Some specialty shops in major shopping centres open later in the morning but will stay open until 6pm or 7pm Monday to Friday, with 9am-5pm trading on weekends. Supermarkets in these centres may open for 24 hours or from very early in the morning until very late at night.