1, open the invoice: open your invoice, pay attention to confirm whether the invoice is a formal machine-printed invoice.

2, find the invoice date: in the invoice to find the "invoice date" column, usually located in the invoice number below or to the right.

3, confirm the time: in the "invoice date" column, usually labeled with the month and year and specific time, such as June 15, 2021 15:30, that the invoice is issued in this time period.