cmd batch file check if current hour is equal to one of specific hour - datetime

Question

I would like to develop a batch file to check the current time hour is equal to specific hour.
As long as n+2 hour (e.g. 0, 2, 4, 6, 8, 10, etc...) is matched with system current hour, it will echo to valid message, otherwise it will echo to invalid message.
Anyone can help me? Thanks.
Source Code
FOR /F %%a IN ('Powershell -Nop -c "Get-Date -Format 'HH'"') DO SET getcurrHour=%%a
FOR /L %%a IN (0,2,22) DO SET hourList=%%a
IF %getcurrHour% == %hourList% (
ECHO It's valid.
) ELSE (
ECHO It's not valid.
)

Answer 1

If you're using PowerShell anyhow, then let it do more of the work for you.
#%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe -NoProfile^
"$Hr = (Get-Date).Hour;"^
"If (((($Hr / 2) - [Math]::Truncate($Hr / 2)) * 10) -Eq 5)"^
"{ Write-Host \"It's not valid.\" }"^
"Else { Write-Host \"It's valid.\" }"
#Pause
The #Pause is included only for users testing directly from the GUI, for others it can be omitted
Just to reduce the amount of code I used to prove a point, here's a more specific example for the task you've laid out in your question, i.e. determining whether the hour is odd or even:
#powershell.exe -NoP "If (((Get-Date).Hour %% 2) -Eq 1) { Write-Host \"It's not valid.\" } Else { Write-Host \"It's valid.\" }"
#Pause
Once again the pause is only required for users invoking the batch file via the GUI.
And because inevitably, you're going to tell us that you're not really wanting to print messages to the screen, but to perform different actions based upon the odd or even result:
#For /F %%G In ('powershell.exe -NoP "(Get-Date).Hour %% 2"') Do #If %%G Equ 1 (Echo It's not valid) Else Echo It's Valid.
#Pause

Answer 2

FOR /F %%a IN ('Powershell -Nop -c "Get-Date -Format 'HH'"') DO SET getcurrHour=%%a
set /a "check=(1%getcurrhour%-100) %%2"
if "%check%" == "0" (
echo even hour
) else (
echo odd hour
)
I guess, the line set /a "check=(1%getcurrhour%-100) %%2 needs some explanation:
set /a also knows octal numbers. They start with a zero. 08 and 09 start with a zero, but are not valid octal numbers, so we would get a syntax error. So we precede it with a 1 and subtract 100 from that to get a valid decimal number (8) The we simply do a MOD 2 to get a zero for even numbers and a one for odd numbers.

Answer 3

You need to test each value in the loop, not set the last value and test.
There is another issue however. Powershell's date is returned as HH which will do:
02
etc
22
Where your for /L loop gives:
2
etc
22
Meaning for some numbers it will not be true. So we need to test if the loop is single digit or double, if single we add a leading 0
#echo off
setlocal enabledelayedexpansion
for /f %%a in ('Powershell -Nop -c "Get-Date -Format 'HH'"') do set "getcurrHour=%%a"
for /L %%a IN (0,2,22) do (
set "li=%%~a"
if "!li:~1!" == "" set "li=0!li!"
if %getcurrHour% equ !li! (
echo It's valid.
) else (
echo It's not valid.
)
)