You can use the Time.String() method to convert a time.Time to a string. This uses the format string "2006-01-02 15:04:05.999999999 -0700 MST".
If you need other custom format, you can use Time.Format(). For example to get the timestamp in the format of yyyy-MM-dd HH:mm:ss use the format string "2006-01-02 15:04:05".
Example:
t := time.Now()
fmt.Println(t.String())
fmt.Println(t.Format("2006-01-02 15:04:05"))
Output (try it on the Go Playground):
2009-11-10 23:00:00 +0000 UTC
2009-11-10 23:00:00
Note: time on the Go Playground is always set to the value seen above. Run it locally to see current date/time.
Also note that using Time.Format(), as the layout string you always have to pass the same time –called the reference time– formatted in a way you want the result to be formatted. This is documented at Time.Format():
Format returns a textual representation of the time value formatted according to layout, which defines the format by showing how the reference time, defined to be
Mon Jan 2 15:04:05 -0700 MST 2006would be displayed if it were the value; it serves as an example of the desired output. The same display rules will then be applied to the time value.