Retrieve datetime object in Powershell without the time portion - powershell

Question

Is it possible to retrieve only the date portion of a datetime object in PowerShell? Reason being I need to compare the LastWriteTime property of files with today's date to determine whether to backup a file or not. As-is a datetime object includes the time as well which will always evaluate to false when I do something like:
if ($fileDate -eq $currentDate) {
# Do backup
}
I haven't found anyway to do this. If we use the format operator or a method, it converts the object to a string object. If you try to convert that back to a datetime object, it appends the time back onto the object. Probably something simple, but I've been looking at this script for a while and that's the last part that's breaking.

Answer 1

EDIT: As #jessehouwing points out in the comments below, my answers are unnecessarily complicated. Just use $datetime.Date.
A couple of ways to get a DateTime without any time component (ie set to midnight at the start of the date in question, 00:00:00):
$dateTime = <some DateTime>
$dateWithoutTime = $dateTime.AddSeconds(-$dateTime.Second).AddMinutes(-$dateTime.Minute).AddHours(-$dateTime.Hour)
or
$dateTime = <some DateTime>
$dateWithoutTime = Get-Date -Date ($dateTime.ToString("yyyy-MM-dd"))
I ran each version in a loop, iterating 100,000 times. The first version took 16.4 seconds, the second version took 26.5 seconds. So I would go with the first version, although it looks a little more complicated.
Based on answers found here: https://techibee.com/powershell/powershell-how-to-query-date-time-without-seconds/2737 (that article is about stripping just the seconds from a DateTime. But it can be extended to stripping hours, minutes and seconds).

Answer 2

Assuming $fileDate is not a dateTime object, then you can just convert both to strings and format them.
if ($fileDate.ToString() -eq $currentDate.ToString("dd/MM/yyyy")) {
# Do backup
}

Answer 3

This will not answer how to remove time on datetime, but to do your validation purpose of identifying when to backup.
I do suggest to subtract your two given date values and compare the result if total hours are already met to do your backup.
if (( $currentDate - $fileDate ).TotalDays > 7) {
# Do Backup
}
you can also validate for the following
Days :
Hours :
Minutes :
Seconds :
Milliseconds :
Ticks :
TotalDays :
TotalHours :
TotalMinutes :
TotalSeconds :
TotalMilliseconds :

Answer 4

Assuming $currentTime contains a DateTime object, you can retrieve a new DateTime object with the same date but with the time portion zeroed like this:
$midnight = Get-Date $currentTime -Hour 0 -Minute 0 -Second 0 -Millisecond 0