linux: added date, time, timezone and hwclock guides

wiki/linux/arch-linux/installation.md

@@ -138,7 +138,12 @@ en_US.UTF-8 UTF-8
 
 - `locale-gen` - Generate languages
 - `echo KEYMAP=de-latin1-nodeadkeys > /etc/vconsole.conf` - set the keymap
-- `tzselect` - Set region
+- `cp /usr/share/zoneinfo/Europe/Berlin /etc/localtime` - set your timezone
+  (select the first file accordingly to your location)
+- `date +%Y%m%d -s "<yyyymmdd>"` - set the current date (change
+  values accordingly)
+- `date +%T -s "<hh:mm:ss>"` - set the current time (change values accordingly)
+- `hwclock -w` - sync the current date and time with the hardware clock
 
 ## 9. Configure and create kernel-image
 

wiki/linux/date.md

@@ -0,0 +1,39 @@
+# Date
+
+`date` is a program to show and edit the date and time of a system.
+To change the hardware clock look at the [according article](./hwclock.md)
+
+## Display time and date
+
+To change the time and date run the following command:
+
+```shell
+date
+```
+
+## Change the date and time
+
+To change the date run the following command with an adjusted value for the
+date:
+
+```shell
+date +%Y%m%d -s "20210809"
+```
+
+To change the time run the following command with an adjusted value for the
+date:
+
+```shell
+date +%T -s "18:49:42"
+```
+
+After that you can check if the time is correct by displaying it.
+
+## Set timezone
+
+To set your timezone run the following command with the accordingly selected
+file for your location:
+
+```shell
+cp /usr/share/zoneinfo/Europe/Berlin /etc/localtime
+```

wiki/linux/hwclock.md

@@ -0,0 +1,19 @@
+# HWClock
+
+`hwclock` is a program to set and display the hardware clock.
+
+## Display time and date
+
+To display the hardware clock run the following command:
+
+```shell
+hwclock
+```
+
+## Sync the hardware clock to the system time
+
+To sync the hardware clock run the following command:
+
+```shell
+hwclock -w
+```