Time formats
Timestamp fields should be one of the standard JavaScript date format as specified int the MDN Date documentation.
For example, the following list has different valid timestamp formats. Your time field can be one of this format:
year,population
2017,8
2017-02,9
2017-03,9.3
2017/04,9.4
2017/05/23,9.4
2017-06-25T12:10:00Z,10.1
"July 12, 2017 03:24:00",12
2017/08/23 10:30,9.4
2017/09/23 10:30:20,9.4
2017-10-23 10:30:20,9.4
Thu Nov 23 2017 10:30:20 GMT+0000 (Greenwich Mean Time),10.1
"Sat, 23 Dec 2017 10:30:20 GMT",12
01/29/2018,12.4
UNIX EPOCH Time formats
If your data is in UNIX epoch time formats (unix milliseconds format), you can select Timestamp ( UNIX ms ) / timestamp_epoch as as type:
Year,Population
1262304000000,200
1293840000000,201
In the above example, first row represents year 2010 and second row represents 2011.
UNIX epoch time also supported. You can select Timestamp ( UNIX s ) / timestamp_epoch_s as type if your API data is in seconds.