How to? Find Previous Day Subroutine

[scottvk]

Below is a set of TCC subroutines that will find the previous day

• Finds last day of previous month if necessary
• Accounts for 1st day of year
• Accounts for Leap Year

GOSUB GET_DATE
echo input date is %inputMonth%/%inputDay%/%inputYear%
EXIT

REM *** SUBROUTINES GO BELOW ***
:GET_DATE

set inputYear=%@substr[%@dateconv[%date,4],0,4]
set inputMonth=%@substr[%@dateconv[%date,4],5,2]
set inputDay=%@substr[%@dateconv[%date,4],8,2]
GOSUB DETERMINE_PREVIOUS_DAY​

RETURN
:DETERMINE_PREVIOUS_DAY
REM SUBTRACT 1 FROM CURRENT DAY

SET inputDay=%@eval[%inputDay%-1]
IFF %inputDay == 0 THEN & set inputMonth=%@eval[%inputMonth%-1]
GOSUB DETERMINE_LAST_DAY_OF_PREVIOUS_MONTH
&ENDIFF​

RETURN
:DETERMINE_LAST_DAY_OF_PREVIOUS_MONTH

IFF %inputMonth == 0 THEN & set inputMonth=12 & set inputYear=%@eval[%inputYear-1] &ELSEIFF %inputMonth LT 10 THEN & set inputMonth=0%inputMonth% &ENDIFF
REM
echo input MM/Day is %inputMonth%/%inputDay
REM 31 days in month - Jan,Mar,May,Jul,Aug,Oct,Nov
REM @WILD[string1,string2] : Compares two strings and returns 1 if they match or 0 if they don't match. **Does *NOT* work with Variable in string 1**
IFF %@WILD[01030507081012,*%inputMonth%*] EQ 1 THEN & SET inputDay=31
REM 30 days in month - Apr,Jun,Sep,Nov
ELSEIFF %@WILD[04060911,*%inputMonth%*] EQ 1 THEN & SET inputDay=30
REM Determine if last day of February is 28 or 29th (due to leap year)
ELSE GOSUB FEBRUARY_PROC
ENDIFF​

RETURN
REM
REM Check if date is Leap Year (year is divisible by 4 *AND* (Year is *NOT* divisible 100 OR Year *IS* divisible 100 & also 400))
:FEBRUARY_PROC

IFF %@eval[%inputYear MOD 4] != 0 THEN &(SET inputDay=28)
&ELSEIFF %@eval[%inputYear MOD 100] != 0 THEN &(SET inputDay=29)
&ELSEIFF %@eval[%inputYear MOD 400] = 0 THEN &(SET inputDay=29)&ELSE& SET inputDay=28
&ENDIFF​

RETURN

 

[TimButterfield]

Here is a shorter way of getting the last day of the prior month (relative to the current date month):

echo %@makedate[%@eval[%@date[%_month/1/%_year]-1]]

You can make that an alias and then wrap in @execstr[...] to use as a function. If you want to pass an input date, you can get that month with %@month[%InputDate] or use %@if to make the InputDate optional.

 

[samintz]

If all you want is the date of the previous day, then why not just do:

echo %@agedate[%@eval[%@makeage[%_date] - 864000000000]]
or 
echo %@makedate[%@dec[%@date[%_date]]]

 

[scottvk]

Thanks, that's good to know.

 

[samintz]

If all you want is the date of the previous day, then why not just do:

echo %@agedate[%@eval[%@makeage[%_date] - 864000000000]]
or
echo %@makedate[%@dec[%@date[%_date]]]

You can specify your own dates also instead of using %_date.

function prevday=`%@makedate[%@dec[%@date[%1]]]`
echo %@prevday[%_date]
08/11/16

echo %@prevday[3/1/16]
02/29/16