date convert to days

[nguyenb9]

How do you convert the past date such as 01/01/2001 to current days.

Thanks,
Bao

 

[olded]

Hi:

Take a look at this thread over in the unix scripting thread:

thread822-514837

Regards,

Ed

 

[nguyenb9]

Sorry! that is not what I am looking for. I am looking for the date that can convert it to how many days. For example from 12/29/2002 to 04/21/2003 is 113 days.

thanks

 

[olded]

Hi:

Let's take a closer look (this is ksh):

JD1229=$(get_JD 29 12 2002) # Julian date 12/29/2002
JD0421=$(get_JD 21 4 2003) # Julian date 4/21/2003
diff=$((JD0421-JD1229))
echo $diff # should be 113

Regards,


Ed

 

[nguyenb9]

I put the script together, don't seem to work. Can you tell me what is wrong?

#!/bin/ksh
set -x
get_JD ()
{
typeset -i JDD
JD1229=$(get_JD 29 12 2002) # Julian date 12/29/2002
JD1229=$(get_JD 29 12 2002) # Julian date 12/29/2002
diff=$((JD0421-JD1229))
echo $diff # should be 113
}

thanks,

 

[olded]

get_JD is a ksh function:

#!/bin/ksh

# The Julian date (JD) is a continuous count of days from 1 January 4713 BC.
# The following # algorithm is good from years 1801 to 2099
# See URL:

http://aa.usno.navy.mil/faq/docs/JD_Formula.html

for more information
get_JD ()
{
typeset -i JDD

JDD=$(($1-32075+1461*($3+4800+($2-14)/12)/4+367*($2-2-($2-14)/12*12)/12-3*(($3+4
900+($2-14)/12)/100)/4))
echo $JDD
} # end get_JD

JD1229=$(get_JD 29 12 2002) # Julian date 12/29/2002
JD0421=$(get_JD 21 4 2003) # Julian date 4/21/2003
diff=$((JD0421-JD1229))
echo $diff # should be 113

 

[nguyenb9]

Thank you very much! It is working.