Merge pull request #344 from deepikabhavnani/rtc_time

RTC and time API pages updated

Author: Amanda Butler

docs/reference/api/platform/Rtc.md

@@ -1 +1,17 @@
-## Rtc
+## RTC
+
+The RTC (Real-Time Clock) class provides mechanisms to set the current time of the hardware RTC with `set_time` API. The time is set as an offset measured in seconds from the time epoch (Unix Epoch - January 1, 1970). 
+
+You can use the `attach_rtc` API to hook external RTC for using C time functions. It provides you with `init()`, `read()`, `write()` and `isenabled()` functions to be attached. <a href="/docs/v5.6/reference/time.html" target="_blank">Time</a> provides more information about C `date` and `time` standard library functions.
+
+RTC class APIs are thread safe.
+
+RTC can keep track of time even in a powered down state if the secondary source of power (battery) is connected.
+
+### RTC Time class reference
+
+[![View code](https://www.mbed.com/embed/?type=library)](https://os.mbed.com/docs/v5.6/mbed-os-api-doxy/mbed__rtc__time_8h_source.html)
+
+### RTC Time example
+
+[![View code](https://www.mbed.com/embed/?url=https://os.mbed.com/teams/mbed_example/code/time_HelloWorld/)](https://os.mbed.com/teams/mbed_example/code/time_HelloWorld/file/8593c9813840/main.cpp)

docs/reference/api/platform/Time.md

@@ -1,8 +1,16 @@
 ## Time
 
-The C date and time functions are a group of functions in the standard library of the C programming language implementing date and time manipulation operations. They provide support for time acquisition, conversion between date formats and formatted output to strings.
+The C `date` and `time` functions are a group of functions in the standard library of the C programming language implementing date and time manipulation operations. They provide support for time acquisition, conversion between date formats and formatted output to strings.
 
-### Time hello, world
+You can convert time to a human-readable format using `ctime`, `localtime`, `strftime` and other C standard functions.
+
+You cannot use `mktime` and `localtime` C standard library functions in an interrupt handler with the GCC toolchain. We have added dedicated routines `_rtc_mktime` and `_rtc_localtime`, which are optimized and faster then C standard library functions, to overcome this issue.
+
+### RTC Time class reference
+
+[![View code](https://www.mbed.com/embed/?type=library)](https://os.mbed.com/docs/v5.6/mbed-os-api-doxy/mbed__mktime_8h_source.html)
+
+### Time example
 
 [![View code](https://www.mbed.com/embed/?url=https://os.mbed.com/teams/mbed_example/code/time_HelloWorld/)](https://os.mbed.com/teams/mbed_example/code/time_HelloWorld/file/8593c9813840/main.cpp)