A Potential Challange in SharePoint 2013 Calendar
I’ve recently been working on a project for an intranet site using SharePoint 2013 Calendar on-Premises and encountered an issue when displaying an all-day event in search results. It actually shows as one day earlier. This only happens to an event item when “All Day” flag is enabled.
In our case scenario, a Search Result Web Part is configured to query against an Event Calendar list and display content in a customized display template for branding purposes. We created an all-day event for December 25 but it actually showed up on December 24 which begun at 8pm in our customized display template! I checked on the data from this list, and the start time for this event (December 25 at 12:00am) was correct(see caption 2). Why is an all-day event not rendered properly and where is this offset coming from?
A bit of our background here: our SharePoint server has been configured its default time zone to EST (Eastern Standard Time). This applies to the default time zone at the top level web application level as well as an individual site collection and user.
When you create a new calendar event item, SharePoint server 2013 stores raw date values into the SQL database using the Coordinated Universal Time (UTC) regardless of what time zone is configured for the current user. This SharePoint event will then be shared across time zone and adjusted to the time local as has been configured in SharePoint Settings.
In our case, we configured refiners for our search results and event’s start time is being mapped to a managed property, RefinableDate00. RefinableDate00 is of a DateTime data type that includes the Event Start Time to the index for a more refined search results experience. What happened is that the date value that is returned to this managed property is not being offset by SharePoint server. It returned the time value in UTC which is 4 hours earlier than user’s time zone (EST) (or 5 hours earlier during the Daylight Saving Time).
var eventDate = New Date(ctx.CurrentItem.RefinableDate00)
where start date of an event is mapped to RefinableDate00
Conversely, you can use a method such as getUTCHours() to get the hour in local time offset from UTC/GMT.