[R] problems in vectors of dates_times

[Troels Ring]

Dear friends - I have further problems  handling dates_times, as 
demonstrated below where concatenating two formatted vectors of 
date_times results in errors.
I wonder why this happens and what was wrong in trying to take these two 
vectors together
All best wishes
Troels Ring
Aalborg, Denmark
Windows
R version 3.3.2 (2016-10-31)


A <- structure(c(1364450400, 1364450400, 1364536800, 1364623200, 
1364709600,
1364796000, 1364882400, 1364968800, 1365055200, 1365141600, 1365228000,
1365314400, 1365400800), class = c("POSIXct", "POSIXt"), tzone = "UTC")
A
B <- structure(c(1365141600, 1365228000, 1365314400, 1365400800, 
1365487200,
1365573600, 1365660000, 1365746400, 1365832800, 1365919200, 1366005600,
1366092000), class = c("POSIXct", "POSIXt"), tzone = "UTC")
B
C <- c(A,B)
C