Epoch time conversion using datetime function

Hello i am trying to convert epoch time to date time using following command

datetime(1653128376288, 'convertfrom', 'posixtime', 'Format', 'MM/dd/yyyy HH:mm:ss.SSS','TimeZone','Europe/Zurich') and

the answer comes to be 07/22/54355 08:44:48.000 which is obviously wrong,

however if i use an online tool (see below) than it gives me the correct answer. Can anyone help me to find what wrong? i need to convert an array of 30000 rows. thanx

Answer 1

[Stephen23]

Your value is in milliseconds (not seconds, as is standard for Unix time), so either divide the value by 1000:

opt = {'Format', 'eeee dd MM yyyy HH:mm:ss.SSS'};
datetime(1650000000000/1000, opt{:}, 'convertfrom','posixtime')

ans = datetime
   Friday 15 04 2022 05:20:00.000

or specify the 'tickspersecond' option:

datetime(1650000000000, opt{:}, 'convertfrom', 'epochtime','Epoch','1-Jan-1970','TicksPerSecond',1000)

ans = datetime
   Friday 15 04 2022 05:20:00.000

Answer 2

[Karim]

One approach would be to add the "ticks per second" parameter, in your case set it to 1000:

EpochVal = 1650000000000;

% convert epoch time
MyTime = datetime(EpochVal,'ConvertFrom','epochtime','Epoch','1970-01-01','TicksPerSecond',1000)

MyTime = datetime
   15-Apr-2022 05:20:00

% convert to the required format
MyFormattedTime = datetime(MyTime,'Format','MM/dd/yyyy HH:mm:ss.SSS','TimeZone','Europe/Zurich')

MyFormattedTime = datetime
   04/15/2022 05:20:00.000