您只需要查看6个月前的月份,并确定其中的一半:
DateTime start, end;
var date = DateTime.Today.AddMonths(-6);
var month = date.Month;
var year = date.Year;
if (month <= 6) {
start = new DateTime(year, 1, 1);
end = new DateTime(year, 6, 30);
} else {
start = new DateTime(year, 7, 1);
end = new DateTime(year, 12, 31);
}
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