[질문]리눅스에서 시간이 계속 안맞습니다.

       It works like this: hwclock keeps a file, /etc/adjtime, that keeps some historical information.  This  is  called  the
       adjtime file.
 
       Suppose  you start with no adjtime file.  You issue a hwclock --set command to set the Hardware Clock to the true cur-
       rent time.  Hwclock creates the adjtime file and records in it the current time as the last time the clock  was  cali-
       brated.   5  days later, the clock has gained 10 seconds, so you issue another hwclock --set command to set it back 10
       seconds.  Hwclock updates the adjtime file to show the current time as the last time the  clock  was  calibrated,  and
       records  2  seconds  per day as the systematic drift rate.  24 hours go by, and then you issue a hwclock --adjust com-
       mand.  Hwclock consults the adjtime file and sees that the clock gains 2 seconds per day when left alone and  that  it
       has been left alone for exactly one day.  So it subtracts 2 seconds from the Hardware Clock.  It then records the cur-
       rent time as the last time the clock was adjusted.  Another 24 hours goes by and you issue another  hwclock  --adjust.
       Hwclock  does  the same thing: subtracts 2 seconds and updates the adjtime file with the current time as the last time
       the clock was adjusted.
 
       Every time you calibrate (set) the clock (using --set or --systohc ), hwclock recalculates the systematic  drift  rate
       based  on  how long it has been since the last calibration, how long it has been since the last adjustment, what drift
       rate was assumed in any intervening adjustments, and the amount by which the clock is presently off.
 
       A small amount of error creeps in any time hwclock sets the clock, so it refrains from making an adjustment that would
       be less than 1 second.  Later on, when you request an adjustment again, the accumulated drift will be more than a sec-
       ond and hwclock will do the adjustment then.
 
       It is good to do a hwclock --adjust just before the hwclock --hctosys at system startup time, and  maybe  periodically
       while the system is running via cron.
 
       The  adjtime  file,  while  named  for its historical purpose of controlling adjustments only, actually contains other
       information for use by hwclock in remembering information from one invocation to the next.
 
       The format of the adjtime file is, in ASCII:
 
       Line 1: 3 numbers, separated by blanks: 1) systematic drift rate in  seconds  per  day,  floating  point  decimal;  2)
       Resulting  number  of  seconds  since 1969 UTC of most recent adjustment or calibration, decimal integer; 3) zero (for
       compatibility with clock(8)) as a decimal integer.
 
       Line 2: 1 number: Resulting number of seconds since 1969 UTC of most recent calibration.  Zero if there  has  been  no
       calibration yet or it is known that any previous calibration is moot (for example, because the Hardware Clock has been
       found, since that calibration, not to contain a valid time).  This is a decimal integer.
 
       Line 3: "UTC" or "LOCAL".  Tells whether the Hardware Clock is set to Coordinated Universal Time or local  time.   You
       can always override this value with options on the hwclock command line.