rtc

Set or get date from realtime clock (BlackBerry 10 OS)

You must be root to run this utility.

Syntax:

Update the current time based on the time from the specified clock:

rtc [-b [base][,[reg_shift][,[mem_map][,c_offset]]]]
    [-l] [-r rate] [-S seconds] clock_type

Set the time of the specified clock to the current time:

rtc [-b [base][,[reg_shift][,[mem_map][,c_offset]]]]
    -s [-l] clock_type

Options:

-b [base][,[reg_shift][,[mem_map][,c_offset]]]
The location of the RTC chip:
  • base — the base address of the chip.
  • reg_shift — spacing of the device registers as a power of 2. For example:
    0
    Registers are 1 byte apart.
    1
    Registers are 2 bytes apart.
    2
    Registers are 4 bytes apart.

    n
    Registers are 2 n bytes apart.

    The default reg_shift is 0.

  • mem_map — memory or I/O space.
  • c_offset — offset to the century byte in NVRAM.
-l
("el") Set hardware time to local time, not Coordinated Universal Time (UTC). UTC is the standard term for Greenwich Mean Time (GMT). The -l option has no effect if the clock_type is net.
-r rate
Rate at which to adjust the OS time if it's currently within 60 seconds (or value set by -S) of the time from the source specified by clock_type. The rate is turned into a percentage 1/rate. The default rate is 100 (1%).
-S seconds
Specify the maximum number of seconds difference between current time and new time before jam loading rather than slowly adjusting. (see -r for the convergence speed). Default: 60.
-s
Set hardware to current date and time.
clock_type
One of the following:
Clock type Description
hw Hardware clock (automatically selects one based on information provided by the startup)
at (deprecated) IBM PC/AT Compatible hardware clock
ds1386 Embedded Dallas Semiconductor DS1386
ps2 (deprecated) IBM PS/2 Compatible hardware clock
rtc72423 Embedded Fox RTC-72423
mc146818 IBM PC/AT Compatible hardware clock
m48t5x STMicroelectronics TIMEKEEPER Series clock
net [node] Hardware clock on a remote node

Description:

The rtc command gets or sets the date and time from a battery backed-up hardware clock.

If your machine has a builtin clock/calendar, you should include the following command in your startup script so BlackBerry 10 OS automatically reads the time when the system starts:

rtc hw

You can use clock type net [node] to get the date from a specified node, or to set the date on a specified node. If node isn't specified, the default is the local machine. When clock type net [node] is used, the -l option has no effect.

Be careful if you set the date during the period that a time zone is switching to daylight saving time (DST). When a time zone changes to DST, the local time goes back one hour (for example, 2:00 a.m. becomes 1:00 a.m.). The local time during this hour is ambiguous (e.g. 1:14 a.m. occurs twice in the morning that the time zone switches to DST). To avoid problems, use UTC time to set the date in this period.

Examples:

Update the current date and time from the hardware clock:

rtc hw

Set hardware clock with current date and time:

rtc -s hw

Exit status:

0
Successful.
>0
An error occurred.

Last modified: 2014-06-24



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