This part of IEC 62054 specifies particular requirements for the type test of newly manufactured indoor time switches with operation reserve that are used to control electrical loads@ multi-tariff registers and maximum demand devices of electricity metering equipment. The time switch keeps the real time@ it may keep the date@ it may be capable of handling leap years@ it may support daylight saving@ i.e. it modifies the deviation of local time to GMT according to the relevant regulations. The time switch may have a synchronization capability. The time switch also holds a schedule of switching actions@ which may be specified in terms of time@ day of the week@ date within a month or a year. The time switch controls the output elements depending on the time and the schedule of switching actions stored. This standard gives no requirements for constructional details internal to the time switch. In the case where time switch functionality is integrated into multifunction electricity metering equipment@ the relevant parts of this standard apply. This standard covers time switches with analogue mechanical dials or electronic digital displays that are ?C synchronous; or ?C crystal-controlled. This standard does not cover the acceptance tests and the conformity tests. Nevertheless@ an example of what could be an acceptance test is given in Annex A . The dependability aspect is covered by the documents of the IEC 62059 series. When using this standard in conjunction with IEC 62052-21@ the requirements of this standard take precedence over those of IEC 62052-21 with regard to any item already covered in it.