bug#40220: date command set linux epoch time failed

[shy]

Hi all:


I use command     date -s "1970-01-20 00:00:00" to set date, but it failed.  
there is error message "date: can't set date: Invalid argument".
 It's UTC time and no timezone.


I test with stime or settimeofday to set seconds 0, they are all have the 
problem.


1. I use buildroot-2013.05, the busybox is in 1.21.1, the linux kernel is in 
version 4.4.39.


# date -s "1970-01-20 00:00:00"
Tue Jan 20 00:00:00 UTC 1970
# date -R
Tue, 20 Jan 1970 00:00:03 +0000
# date -s "1970-01-01 00:00:00"
date: can't set date: Invalid argument
Thu Jan  1 00:00:00 UTC 1970


2. I test in ubuntu version 14.04.1.
shy@ubuntu:/etc$ sudo date -s "2020-03-01 00:00:00"
Sun Mar  1 00:00:00 UTC 2020
shy@ubuntu:/etc$ date -R
Sun, 01 Mar 2020 00:00:03 +0000

shy@ubuntu:/etc$ sudo date -s "1970-01-01 00:00:00"

date: cannot set date: Invalid argument

Thu Jan  1 00:00:00 UTC 1970

shy@ubuntu:/etc$ uname -a

Linux ubuntu 4.4.0-142-generic #168~14.04.1-Ubuntu SMP Sat Jan 19 11:26:28 UTC 
2019 x86_64 x86_64 x86_64 GNU/Linux




3.When set date command, the busybox uses function "stime" to set time, I use 
stime to set time around  linux epoch time,

   but the stime seems not work well.

   int ret = 0;

   time_t time = 20;

   ret = stime(&time);

   printf("ret %d %d\r\n",ret, errno);

   perror("stime:");

and the results are as follows:

    ret -1 22

    stime:: Invalid argument




Best regards!