Compare DateTime to Text

Hi All,

I'm trying to manually specify a datetime to use in a formula but can't get it to work, I orignially used the datevalue function but have discovered it ignores the time.

My measure is

=calculate(
	[Measure1],
		Table1[startdate]<="20/02/15 12:00:00"
		,Table1[enddate]>="2016/02/15 12:00:00"
		,Table1[Application_date]<datevalue("2017/02/16")
		,Table1[year] ="17/18"
)

Any idea how I can work around this? Its crusical that the time is used as the records can change several times a day so we need to specify a time down to the second.

Any help appreciated