// https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/show-text-dates-times
// https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/functions/function-dateadd-datediff
public static FormulaValue DateAdd(IRContext irContext, FormulaValue[] args)
{
DateTime datetime;
switch (args[0])
{
case DateTimeValue dtv:
datetime = dtv.Value;
break;
case DateValue dv:
datetime = dv.Value;
break;
default:
return(CommonErrors.RuntimeTypeMismatch(irContext));
}
var delta = (NumberValue)args[1];
var units = (StringValue)args[2];
try
{
DateTime newDate;
switch (units.Value.ToLower())
{
case "milliseconds":
newDate = datetime.AddMilliseconds(delta.Value);
break;
case "seconds":
newDate = datetime.AddSeconds(delta.Value);
break;
case "minutes":
newDate = datetime.AddMinutes(delta.Value);
break;
case "hours":
newDate = datetime.AddHours(delta.Value);
break;
case "days":
newDate = datetime.AddDays(delta.Value);
break;
case "months":
newDate = datetime.AddMonths((int)delta.Value);
break;
case "quarters":
newDate = datetime.AddMonths((int)delta.Value * 3);
break;
case "years":
newDate = datetime.AddYears((int)delta.Value);
break;
default:
// TODO: Task 10723372: Implement Unit Functionality in DateAdd, DateDiff Functions
return(CommonErrors.NotYetImplementedError(irContext, "DateAdd Only supports Days for the unit field"));
}
if (args[0] is DateTimeValue)
{
return(new DateTimeValue(irContext, newDate));
}
else
{
return(new DateValue(irContext, newDate.Date));
}
}
catch
{
return(CommonErrors.ArgumentOutOfRange(irContext));
}
}
public static FormulaValue DateDiff(IRContext irContext, FormulaValue[] args)
{
DateTime start;
switch (args[0])
{
case DateTimeValue dtv:
start = dtv.Value;
break;
case DateValue dv:
start = dv.Value;
break;
default:
return(CommonErrors.RuntimeTypeMismatch(irContext));
}
DateTime end;
switch (args[1])
{
case DateTimeValue dtv:
end = dtv.Value;
break;
case DateValue dv:
end = dv.Value;
break;
default:
return(CommonErrors.RuntimeTypeMismatch(irContext));
}
var units = (StringValue)args[2];
TimeSpan diff = end - start;
// The function DateDiff only returns a whole number of the units being subtracted, and the precision is given in the unit specified.
switch (units.Value.ToLower())
{
case "milliseconds":
double milliseconds = Math.Floor(diff.TotalMilliseconds);
return(new NumberValue(irContext, milliseconds));
case "seconds":
double seconds = Math.Floor(diff.TotalSeconds);
return(new NumberValue(irContext, seconds));
case "minutes":
double minutes = Math.Floor(diff.TotalMinutes);
return(new NumberValue(irContext, minutes));
case "hours":
double hours = Math.Floor(diff.TotalHours);
return(new NumberValue(irContext, hours));
case "days":
double days = Math.Floor(diff.TotalDays);
return(new NumberValue(irContext, days));
case "months":
double months = (end.Year - start.Year) * 12 + end.Month - start.Month;
return(new NumberValue(irContext, months));
case "quarters":
double quarters = (end.Year - start.Year) * 4 + Math.Floor(end.Month / 3.0) - Math.Floor(start.Month / 3.0);
return(new NumberValue(irContext, quarters));
case "years":
double years = end.Year - start.Year;
return(new NumberValue(irContext, years));
default:
// TODO: Task 10723372: Implement Unit Functionality in DateAdd, DateDiff Functions
return(CommonErrors.NotYetImplementedError(irContext, "DateDiff Only supports Days for the unit field"));
}
}
