Perch Blog post date is 1st January 1970

Whenever my client posts to their blog, the publish date is always 01/01/1970 - not sure why it has started doing this. Any ideas anyone?

The post.html template has the following in:

<div class="hentry">
    <h1><perch:blog id="postTitle" type="text" required="true" size="xl" /></h1>
    <p class="entry-published date"><perch:blog id="postDateTime" format="%d %B %Y" /> 
        <perch:if exists="authorGivenName">by <perch:blog id="authorGivenName" /> <perch:blog id="authorFamilyName" /></perch:if>
    </p>
    <perch:if exists="image">
        <div><img src="<perch:blog id="image" type="image" width="320" height="240" crop="true" label="Image" density="2" />" alt="<perch:blog id="postTitle" />" /></div>
    </perch:if>
    <div class="description entry-content">
        <perch:blog id="postDescHTML" type="textarea" encode="false" editor="ckeditor" textile="true" size="xxl" required="true" />
    </div>
</div>

<perch:blog id="excerpt" type="textarea" label="Excerpt" textile="true" order="1" suppress="true" size="s" />
<perch:blog id="image" type="image" width="50" height="50" crop="true" suppress="true" />

and the diagnostics say this:

PERCH INFORMATION

Perch: 2.4.9
Production mode: Production (100)
Installed apps: content (2.4.9), perch_blog (4.0.3)
DB driver: PDO
DB tables: perch2_blog_authors, perch2_blog_categories, perch2_blog_comments, perch2_blog_posts, perch2_blog_posts_to_categories, perch2_blog_posts_to_tags, perch2_blog_sections, perch2_blog_tags, perch2_content_index, perch2_content_items, perch2_content_regions, perch2_content_resources, perch2_navigation, perch2_navigation_pages, perch2_page_templates, perch2_pages, perch2_resources, perch2_scheduled_tasks, perch2_settings, perch2_user_privileges, perch2_user_role_privileges, perch2_user_roles, perch2_users
Users: 2
App runtimes:
<?php
    include(PERCH_PATH.'/core/apps/content/runtime.php');
    include(PERCH_PATH.'/addons/apps/perch_blog/runtime.php');
?>
Scheduled tasks for perch_blog: delete_spam_comments (1440 mins)
Editor plug-ins: ckeditor, markitup
H1: ceca180a4c1d1af5a341eba838cdaa0d
L1: bfc297f67a9d1df958b1b22ff3c8606d
headerColour: #ffffff
content_singlePageEdit: 1
helpURL:
siteURL: https://www.physiokinetic.co.uk
hideBranding: 1
content_collapseList: 1
lang: en-gb
update_2.2.9: done
latest_version: 2.7.10
headerScheme: light
dashboard: 0
content_hideNonEditableRegions: 0
logoPath: /perch/resources/logo.png
perch_blog_post_url: /blog/post.php?s={postSlug}
perch_blog_update: 4.0
perch_blog_slug_format: %Y-%m-%d-{postTitle}
perch_blog_akismet_key: dc11b21d25c1
perch_blog_comment_notify: 0
on_sale_version: 2.7.10
update_2.4.9: done
perch_blog_max_spam_days: 1
hide_pwd_reset: 0
content_frontend_edit: 0
PERCH_DEVELOPMENT: 10
PERCH_STAGING: 50
PERCH_PRODUCTION: 100
PERCH_DB_USERNAME: jontarbuck
PERCH_DB_SERVER: 213.171.218.249
PERCH_DB_DATABASE: physiokinetic
PERCH_DB_PREFIX: perch2_
PERCH_TZ: Europe/London
PERCH_EMAIL_FROM: jon.tarbuck@mac.com
PERCH_EMAIL_FROM_NAME: Jon Tarbuck
PERCH_LOGINPATH: /perch
PERCH_PATH: /home/fhlinux147/p/physiokinetic.co.uk/user/htdocs/perch
PERCH_CORE: /home/fhlinux147/p/physiokinetic.co.uk/user/htdocs/perch/core
PERCH_RESFILEPATH: /home/fhlinux147/p/physiokinetic.co.uk/user/htdocs/perch/resources
PERCH_RESPATH: /perch/resources
PERCH_HTML5: 1
PERCH_SCHEDULE_SECRET: michael
PERCH_ERROR_MODE: DIE
PERCH_DATE_LONG: %d %B %Y
PERCH_DATE_SHORT: %d %b %Y
PERCH_TIME_SHORT: %H:%M
PERCH_TIME_LONG: %H:%M:%S
PERCH_DEBUG:
PERCH_PREVIEW_ARG: preview
PERCH_TEMPLATE_PATH: /home/fhlinux147/p/physiokinetic.co.uk/user/htdocs/perch/templates
PERCH_DEFAULT_DOC: index.php
PERCH_DEFAULT_EXT: .php
PERCH_PRODUCTION_MODE: 100
PERCH_RWD:
PERCH_HTML_ENTITIES:
PERCH_SSL:
PERCH_AUTH_PLUGIN:
PERCH_DB_CHARSET: utf8
PERCH_DB_PORT:
PERCH_DB_SOCKET:
HOSTING SETTINGS

PHP: 5.2.17
Zend: 2.2.0
OS: Linux
SAPI: cgi-fcgi
Safe mode: not detected
MySQL client: 5.0.95
MySQL server: 5.0.95-log
Extensions: date, libxml, openssl, pcre, zlib, bz2, calendar, ctype, curl, hash, filter, ftp, gettext, gmp, session, iconv, json, mime_magic, pcntl, posix, pspell, readline, Reflection, standard, shmop, SimpleXML, SPL, sockets, exif, sysvmsg, sysvsem, sysvshm, tokenizer, wddx, xml, cgi-fcgi, bcmath, dba, dom, gd, imap, ldap, mbstring, mysql, mysqli, ncurses, odbc, PDO, pdo_mysql, PDO_ODBC, pdo_pgsql, pdo_sqlite, pgsql, snmp, soap, xmlreader, xmlrpc, xmlwriter, xsl, zip, ionCube Loader, Zend Optimizer
GD: Yes
ImageMagick: No
PHP max upload size: 20M
PHP max form post size: 8M
PHP memory limit: 20M
Total max uploadable file size: 8M
Resource folder writeable: Yes
Session timeout: 24 minutes
Native JSON: Yes
Filter functions: Yes
Transliteration functions: No
PHP_FCGI_CHILDREN: 2
PATH: /sbin:/usr/sbin:/bin:/usr/bin
PWD: /var/www/fcgi
PHP_FCGI_MAX_REQUESTS: 100
FCGI_ROLE: RESPONDER
DOCUMENT_ROOT: /home/fhlinux147/p/physiokinetic.co.uk/user/htdocs
HTTP_ACCEPT: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
HTTP_ACCEPT_ENCODING: gzip, deflate
HTTP_ACCEPT_LANGUAGE: en-us
HTTP_CONNECTION: close
HTTP_COOKIE: cmsa=1; PHPSESSID=4ia7l2ku4ca50eho14ia33g794; __utma=185434856.160458481.1420222283.1423142615.1423159660.12; __utmb=185434856.6.10.1423159660; __utmc=185434856; __utmt=1; __utmz=185434856.1420222283.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)
HTTP_HOST: www.physiokinetic.co.uk
HTTP_REFERER: https://www.physiokinetic.co.uk/perch/core/settings/
HTTP_USER_AGENT: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/600.2.5 (KHTML, like Gecko) Version/8.0.2 Safari/600.2.5
HTTP_X_FORWARDED_FOR: 84.19.53.21
HTTP_X_REAL_IP: 84.19.53.21
REDIRECT_REDIRECT_STATUS: 200
REDIRECT_STATUS: 200
REDIRECT_URL: /perch/core/settings/diagnostics/index.php
REMOTE_ADDR: 127.0.0.1
REMOTE_PORT: 34234
SCRIPT_FILENAME: /home/fhlinux147/p/physiokinetic.co.uk/user/htdocs/perch/core/settings/diagnostics/index.php
SERVER_ADDR: 127.0.0.1
SERVER_ADMIN: webmaster@physiokinetic.co.uk
SERVER_NAME: www.physiokinetic.co.uk
SERVER_PORT: 80
SERVER_SOFTWARE: Apache
GATEWAY_INTERFACE: CGI/1.1
SERVER_PROTOCOL: HTTP/1.0
REQUEST_METHOD: GET
REQUEST_URI: /perch/core/settings/diagnostics/
SCRIPT_NAME: /perch/core/settings/diagnostics/index.php
ORIG_SCRIPT_FILENAME: /var/www/fcgi/php-cgi
ORIG_PATH_INFO: /perch/core/settings/diagnostics/index.php
ORIG_PATH_TRANSLATED: /home/fhlinux147/p/physiokinetic.co.uk/user/htdocs/perch/core/settings/diagnostics/index.php
ORIG_SCRIPT_NAME: /fcgi-bin/php-cgi
PHP_SELF: /perch/core/settings/diagnostics/index.php
REQUEST_TIME: 1423160143