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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001181431-07-004957.txt : 20070119
<SEC-HEADER>0001181431-07-004957.hdr.sgml : 20070119
<ACCEPTANCE-DATETIME>20070119170657
ACCESSION NUMBER:		0001181431-07-004957
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070117
FILED AS OF DATE:		20070119
DATE AS OF CHANGE:		20070119

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AUTHENTIDATE HOLDING CORP
		CENTRAL INDEX KEY:			0000885074
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER INTEGRATED SYSTEMS DESIGN [7373]
		IRS NUMBER:				141673067
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		2165 TECHNOLOGY DRIVE
		CITY:			SCHENECTADY
		STATE:			NY
		ZIP:			12308
		BUSINESS PHONE:		5183467799

	MAIL ADDRESS:	
		STREET 1:		2165 TECHNOLOGY DRIVE
		CITY:			SCHENECTADY
		STATE:			NY
		ZIP:			12308

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BITWISE DESIGNS INC
		DATE OF NAME CHANGE:	19930328

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Pai Surendra
		CENTRAL INDEX KEY:			0001307703

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-20190
		FILM NUMBER:		07541469

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		518-346-7799

	MAIL ADDRESS:	
		STREET 1:		C/O AUTHENTIDATE HOLDING CORP
		STREET 2:		2165 TECHNOLOGY DRIVE
		CITY:			SCHENECTADY
		STATE:			NY
		ZIP:			12308
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd143562.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-01-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000885074</issuerCik>
        <issuerName>AUTHENTIDATE HOLDING CORP</issuerName>
        <issuerTradingSymbol>ADAT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001307703</rptOwnerCik>
            <rptOwnerName>Pai Surendra</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>AUTHENTIDATE HOLDING CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>300 CONNELL DRIVE, FIFTH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BERKELEY HEIGHTS</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07922</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Options</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.58</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-01-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>400000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-11-15</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-11-15</value>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>400000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>400000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The reported transactions involved an amendment of outstanding options solely to modify the expiration date to be ten years from the original grant dates.  The options were originally granted on November 15, 2004 and vest as follows: 100,000 vested on the date of grant and the balance of 300,000 vest monthly at the rate of 12,500 per month until all options are vested.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Surendra B. Pai</signatureName>
        <signatureDate>2007-01-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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