Converting timestamp to UTC timezone with XSLT

Question

I have an XML that has timestamp in format like 2016-06-07T07:46:04

I would like to convert timestamp in UTC format like 1465278364 using xslt

How can it be done?

Thanks in advance.

Answer 1

I actually wrote a named template specifically for this a while back. Here it is:

<xsl:template name="converttime">
  <xsl:param name="date" select="."/>
  <xsl:choose>
    <xsl:when test="translate($date,'123456789','000000000') = '0000-00-00T00:00:00'">
      <xsl:value-of select="
        (
          ((substring($date,1,4) - 1970) * 365) + 
          floor((substring($date,1,4) - 1970) div 4) +
          substring(
           '000,031,059,090,120,151,181,212,243,273,304,334,365',
           substring($date,6,2)*4-3, 3
          ) +
          (substring($date,9,2)-1) +
          (1-floor(((substring($date,1,4) mod 4) + 2) div 3))*floor((substring($date,6,2)+17) div 20)
        ) * 86400 +
        (substring($date,12,2)*3600) +
        (substring($date,15,2)*60) +
        substring($date,18,2)
      "/>
    </xsl:when>

    <!-- Unknown format -->
    <xsl:otherwise>-1</xsl:otherwise>
  </xsl:choose>
</xsl:template>

This adds up:

• The number of years since 1970, multiplied by 365.
• The number of leap years since 1970 (i.e., the number of leap days)
• The number of days since the beginning of the year for the given month (not accounting for leap years yet)
• The number of days since the beginning of the month
• 1 if it's a leap year and the month is March or later, otherwise 0 (this formula's fairly horrific, if you really want an explanation let me know in the comments and I'll break it down)

All of the above is then multiplied by the number of seconds in a day Then it's just a simple matter of adding hours * (seconds in an hour), minutes * (seconds in a minute) and seconds.

You can support different date formats just by putting a different <xsl:when> element with a different date pattern, and obviously adjusting the substring calls to match.

Honestly though, only use this if you can't use XSLT 2.0 (or later) or an extension function. Also, I noticed the number you gave is 7200 seconds out from what this produces, but if you're in a time zone 2 hours different from UTC, that's probably why.