Private/Test-DateDifference.ps1
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function Test-DateDifference([array]$date,[datetime]$compare) { # The Test-DateDifference function is used to compare a series of dates against a desired date to find the closest matching date/time # The Rubrik API returns snapshot dates down to the millisecond, but the user may not provide this much detail in their Date argument # A snapshot date may be in the future by milliseconds, but this is considered valid since that is most likely the intent of the user # $date = An array of ISO 8601 style dates (e.g. YYYY-MM-DDTHH:MM:SSZ) # $compare = A single ISO 8601 style date to compare against the $date array # A simple hashtable is created to compare each date value against one another # The value that is closest to 0 (e.g. least distance away from the $compare date) is stored # A "placeholder" value of 1 is used to find the first value within one day of $compare # Otherwise, the date of $null is returned meaning no match Write-Verbose -Message "Finding closest matching date" $datematrix = @{ date = $null value = 1 } foreach ($_ in $date) { # The $c is just a check variable used to hold the total number of days between the current $date item and the $compare value $c = (New-TimeSpan -Start $_ -End $compare).TotalDays # Should we find a value that is less than the existing winning value, store it # Note: 0 would be a perfect match (e.g. 0 days different between what we found and what the user wants in $compare) # Note: Negative values indicate a future (e.g. supply yesterday for $compare but finding a $date from today) # Absolute values are used so negatives are ignored and we find the closest actual match. if ([Math]::Abs($c) -lt $datematrix.value) { $datematrix.date = $_ $datematrix.value = [Math]::Abs($c) } # If $c = 0, a perfect match has been found if ($datematrix.value -eq 0) { break } } If ($null -ne $datematrix.date) { Write-Verbose -Message "Using date $($datematrix.date)" } else { Write-Verbose -Message "Could not find matching date within one day of $($compare.ToString())" } return $datematrix.date } |