Date And -Time Handling Overview

Date And -Time Handling OverviewFunctions that manipulates date and time values. -

Architectural relationships

The system maintains -two clocks:

a secure clock that -can only be set by kernel code or by an application that has TCB capability. -This is a clock that can be used by secure DRM applications.
a non-secure clock that -can be set by applications that require no specific capability. This is the -clock that is used for user-visible time displays.

The non-secure clock is implemented in terms of an offset from the -secure clock.

Both the secure time and the non-secure time can be -set using the System Static Functions API, and specifically:

Secure time

User::SetHomeTimeSecure(0
User::SetUTCTimeSecure()

Non-secure time

User::SetHomeTime()
User::SetUTCTime()

System locale settings, which affect date and time formatting, are -set through TLocale in the Locale Settings API.

Description

The API has three key concepts: point -in time, time utilities, and time interval.

Point -in time

The point in time is a 64-bit integer that represents -time as the number of microseconds since midnight on 1st January 0 AD, using -a nominal Gregorian calendar. It can be set to the current system time, can -have arithmetic and comparison operations performed on it, and can be converted -into a string formatted according to the locale and other options.

The -main point in time interface is provided by TTime. A support -class TDateTime is provided that allows time values to -be get and set in an easy-to-use format, such as year, month, day, rather -than as an integer.

The time value in a TTime object -can be set using either the secure time or the non-secure time.

Time utilities

The time utilities provides miscellaneous time -functions, for such things as checking for leap years.

The time utilities -interface is provided by Time.

Time interval

The time interval represents a period between -two points in time. Time intervals can be added or subtracted, either to or -from each other or to or from points in time.

The time interval interface -is provided by a base class TTimeIntervalBase and by a -family of derived classes for second, minute, hour, etc. intervals. A class -outside this hierarchy, TTimeIntervalMicroSeconds, is provided -for efficiency reasons (it alone stores its value as a 64-bit number).

- -Locale Settings -Overview - -System Static -Functions Overview + + + + + +Date And Time Handling OverviewFunctions that manipulates date and time values. +

Architectural +relationships

The system maintains two clocks:

a secure clock +that can only be set by kernel code or by an application that has +TCB capability. This is a clock that can be used by secure DRM applications.
a non-secure +clock that can be set by applications that require no specific capability. +This is the clock that is used for user-visible time displays.

The non-secure clock is implemented in terms of an offset +from the secure clock.

Both the secure time and the non-secure +time can be set using the System Static Functions API, and specifically:

Secure +time

User::SetHomeTimeSecure(0
User::SetUTCTimeSecure()

Non-secure +time

User::SetHomeTime()
User::SetUTCTime()

System locale settings, which affect date and time formatting, +are set through TLocale in the Locale Settings +API.

Description

The API has three key concepts: point in time, time utilities, +and time interval.

Point in time

The point in time is a 64-bit integer +that represents time as the number of microseconds since midnight +on 1st January 0 AD, using a nominal Gregorian calendar. It can be +set to the current system time, can have arithmetic and comparison +operations performed on it, and can be converted into a string formatted +according to the locale and other options.

The main point +in time interface is provided by TTime. A support +class TDateTime is provided that allows time values +to be get and set in an easy-to-use format, such as year, month, day, +rather than as an integer.

The time value in a TTime object can be set using either the secure time or the non-secure +time.

Time utilities

The time utilities provides miscellaneous +time functions, for such things as checking for leap years.

The time utilities interface is provided by Time.

Time interval

The time interval represents a period +between two points in time. Time intervals can be added or subtracted, +either to or from each other or to or from points in time.

The time interval interface is provided by a base class TTimeIntervalBase and by a family of derived classes for +second, minute, hour, etc. intervals. A class outside this hierarchy, TTimeIntervalMicroSeconds, is provided for efficiency reasons +(it alone stores its value as a 64-bit number).

+ +System Static Functions Overview +Locale +Settings Overview

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