Date must be in the format YYYY-MM-DD or YYYY-MM-DDTHH:MM:SS(((+|-)HH:MM)|Z).
This error occurs when you provide dates that are not in the standard ISO-compliant format.
As an example, February 29, 2008, 1:10:30 p.m. in Seattle should be expressed as:
The ISO standard is based on Greenwich Mean Time (GMT). If you're in the Pacific Time Zone, you are 8 hours off GMT (7 hours off GMT in Daylight Savings). This is indicated by the "-8:00" in the formula above. If you're in the Eastern Time Zone, you are 5 hours off GMT (4 hours off GMT in Daylight Savings).
One common reason why this error occurs is:
If you are using Excel to manage your data, you can format your date columns as text to prevent Excel from automatically reformatting them. To do this: