datetime conversion lose nanoseconds

I have converted an array from epoch time in nanoseconds to datetime using the following:

t(i,1)= datetime(B(i,1),'ConvertFrom','epochtime','TicksPerSecond',1e9,'Format','dd-MMM-yyyy HH:mm:ss.SSSSSSSSS');

the coversion is ok but once opened the array somehow the this part SSSSSSSSS is not displayed at all.

At the same time doing it without a function value per value it works...

How can I solve this issue?

[Stephen23]

ms = intmax('int64');
dt = datetime(ms,'ConvertFrom','epochtime','TicksPerSecond',1e9,'Format','dd-MMM-yyyy HH:mm:ss.SSSSSSSSS')

dt = datetime
   11-Apr-2262 23:47:16.854775807

Answer 1

[Steven Lord]

What Format did you use when you assigned the datetime in the first row of t? Was it one that did not include the nanosecond information?

format1 = 'yyyy-MM-dd HH';
t = datetime('now', 'Format', format1)

t = datetime
   2021-05-21 18

format2 = 'HH-mm-ss ''on'' yyyy-MM-dd';
t(2, 1) = datetime('now', 'Format', format2)

t = 2×1 datetime array
   2021-05-21 18
   2021-05-21 18

The whole array uses format1 because that was the format already in use when you assigned to the second row of t. The second element of t was converted to use the existing format. If you change the array's Format both elements are displayed in the new format.

t.Format = format2

t = 2×1 datetime array
   18-24-27 on 2021-05-21
   18-24-27 on 2021-05-21