Gmail supports a plethora of search operators to help you instantly find that elusive email message buried in your mailbox. You have size search - like
larger_than:5mb - to find the big messages in your account. File search - like
has:attachment filename:doc - will locate email messages that contain file attachments of specific types. This graphic illustrates all the known Gmail search operators that work both on Gmail and Google Inbox.
Date search in Gmail helps you locate emails sent or received in a specific period. Here are some examples:
newer_than:7d from:me- Emails sent in the last 7 days
after:2016/12/01 to:me- Emails received in the month of December 2016
Gmail also supports time-based searches allowing you to find emails in the specific hour, minute or second. For instance, you can limit your Gmail search to emails that were received between Dec 10 8:15 PM and Dec 10, 2016 8:45 PM.
To get started, convert the date and time to Epoch time and then use the timestamp with the standard after or before search operator of Gmail.
For instance, the Epoch time for Dec 10, 2016 8:15 PM is 1481381100 and the Epoch time for Dec 10, 2016 8:45 PM is 1481382900. Use the search query
after:1481381100 before:1481382900 and you’ll get a list of all emails received during that 30-minute period.
Epoch time is the number of seconds that have elapsed since January 1, 1970 (UTC). Use the Epoch converter to represent a human readable date and time in Epoch and use that timestamp with the before or after search operator of Gmail to find that elusive email.