I believe I found a bug in CF11 with DateTime comparisons when dealing with UTC converted values going through serializeJSON then deserializeJSON. I did modify the code to not include the local2utc conversion and that seemed to produce correct results. Can someone please confirm:

<cfscript>
  variables.dttm = createDateTime(2016,04,03,17,53,0);
  variables.dttmutc = dateConvert('local2utc',variables.dttm);

  variables.base = {};
  variables.base.dttmutc_min = dateConvert('local2utc',dateAdd('h',-1,variables.dttm));
  variables.base.dttmutc_max = dateConvert('local2utc',dateAdd('n',1,variables.dttm));

  variables.viajson = deserializeJSON(serializeJSON(variables.base));
  variables.viajson.dttmutc_min = parseDateTime(variables.viajson.dttmutc_min);  // to me this parsing should not be required
  variables.viajson.dttmutc_max = parseDateTime(variables.viajson.dttmutc_max);  // same
</cfscript>
<cfoutput>

  <h1>base</h1>
  dttm = #variables.dttm#<br />
  dttmutc = #variables.dttmutc#<br />
  dttmutc_min = #variables.base.dttmutc_min#<br />
  dttmutc_max = #variables.base.dttmutc_max#<br />
  <br />
  dttmutc GT dttmutc_min = #variables.dttmutc GT variables.base.dttmutc_min#<br />
  dttmutc LT dttmutc_max = #variables.dttmutc LT variables.base.dttmutc_max#<br />

  <h1>via json</h1>
  dttm = #variables.dttm#<br />
  dttmutc = #variables.dttmutc#<br />
  dttmutc_min = #variables.viajson.dttmutc_min#<br />
  dttmutc_max = #variables.viajson.dttmutc_max#<br />
  <br />
  dttmutc GT dttmutc_min = #variables.dttmutc GT variables.viajson.dttmutc_min# (should be YES)<br />  // this is the failing comparison
  dttmutc LT dttmutc_max = #variables.dttmutc LT variables.viajson.dttmutc_max#<br />
</cfoutput>

My results are as follows:

base

dttm = {ts '2016-04-03 17:53:00'}

dttmutc = {ts '2016-04-04 00:53:00'}

dttmutc_min = {ts '2016-04-03 23:53:00'}

dttmutc_max = {ts '2016-04-04 00:54:00'}

dttmutc GT dttmutc_min = YES

dttmutc LT dttmutc_max = YES

via json

dttm = {ts '2016-04-03 17:53:00'}

dttmutc = {ts '2016-04-04 00:53:00'}

dttmutc_min = {ts '2016-04-03 23:53:00'}

dttmutc_max = {ts '2016-04-04 00:54:00'}

dttmutc GT dttmutc_min = NO (should be YES)

dttmutc LT dttmutc_max = YES

BTW, I'm not sure if it matters but my time zone is Pacific Daylight Time (PDT).