Arduino IDE and printing value and current timestamp

I'm working on a project that will get data from my ultrasonic sensor and I want the data to be sent to the firebase. I actually know how this will be done, and I'm getting my results from the sensor but I was wondering if I can also print the current date and time with the value that would be sent to the firebase?

So, I'm currently let's say getting these data:

Current Level: 10
Current Level: 12

I want it to do this:

Current Level: 10.  5:00. 12.2.2019
Current Level: 12.  5:30. 12.2.2019

This is just an example but I want it to grab the current date and time of the actual data transmission.

Where will the date and time information be coming from ?

Since an Arduino doesn't inherently know the time of day, you would need something like a Real Time Clock RTC or if you're connected, Network Time Protocol NTP.

It would make more sense if "the firebase", which is running on a server that does know the date and time, time-stamped the data you send it. I'll be that it actually does, already. You need to look at what "the firebase" can tell you about your data now, and what it could tell you with some configuration changes.

If your'e using GSM to communicate or have access to GPS you could get the time from there. Some transceivers have clocks integrated in them.
Even though, as already suggested by PaulS, you could add date and time upon DB insertion.