Convert Timestamp into Date Vector

I have a timestamp like "x2017_12_1816:00_00". It is in a format "xyyyy_mm_dd_hh:mm:ss". However, matlab will not allow this to convert to a date vector since it's not in an acceptable format. I've been able to convert it to a date format by using the code below, where structFields is a structure containing the unconverted timestamps. As you might imagine, this method takes a long time. I've tried to accomplish the same effect by first converting the timestamps to a number in the format "yyyymmddhhmmss", but have yet to come up with a more efficient algorithm. Any suggestions?

if true
  % code
      structEdit1 = cellfun(@(x) replaceBetween(x,13,15,':','Boundaries','exclusive'),structFields,'UniformOutput',false);
      structEdit2 = cellfun(@(x) replaceBetween(x,16,18,':','Boundaries','exclusive'),structEdit1,'UniformOutput',false);
      structEdit3 = cellfun(@(x) strrep(x(),'_','-'),structEdit2,'UniformOutput',false);
      structEdit4 = cellfun(@(x) insertAfter(x,11,' '),structEdit3,'UniformOutput',false);
      structEdit5 = cellfun(@(x) erase(x,'x'),structEdit4,'UniformOutput',false);
end

Answer 1

[Walter Roberson]

datetime('x2017_12_1816:00_00', 'InputFormat', '''x''yyyy_MM_ddHH:mm_ss', 'Format', 'yyyyMMddHHmmss')

The tricks here:

• datetime uses MM for month and mm for minutes
• datetime uses HH for 24 hour hour
• any alphabetic character that is intended to be used literally must be put inside '' inside the string.

>> disp('''x''yyyy_MM_ddHH:mm_ss')
'x'yyyy_MM_ddHH:mm_ss