**Use case**

Workload generation with continuous queries.

**Describe the solution you'd like**

Similar to now() but non-constant.

{
    registerFunctionToYear(factory);
    registerFunctionToQuarter(factory);
    registerFunctionToMonth(factory);
    registerFunctionToDayOfMonth(factory);
    registerFunctionToDayOfWeek(factory);
    registerFunctionToDayOfYear(factory);
    registerFunctionToHour(factory);
    registerFunctionToMinute(factory);
    registerFunctionToSecond(factory);
    registerFunctionToStartOfDay(factory);
    registerFunctionToMonday(factory);
    registerFunctionToISOWeek(factory);
    registerFunctionToISOYear(factory);
    registerFunctionToCustomWeek(factory);
    registerFunctionToModifiedJulianDay(factory);
    registerFunctionToStartOfMonth(factory);
    registerFunctionToLastDayOfMonth(factory);
    registerFunctionToStartOfQuarter(factory);
    registerFunctionToStartOfYear(factory);
    registerFunctionToStartOfNanosecond(factory);
    registerFunctionToStartOfMicrosecond(factory);