DATE(1) General Commands Manual DATE(1)

date
set date and time

date [
[
[
[
[
cc
]yy
]mm
]dd
]HH
]MM[
.SS
]

As this is too long to fit on one input line, the above solution with Sm is clearly more readable than using Ns and line continuation as follows:
date [
[
[
[
[
cc
]yy
]mm
]dd
]HH
]MM[
.SS
]
September 25, 2015 bsd.lv