Official Docs: gs
The scoped GlideSystem (referred to by the variable name 'gs' in any server-side JavaScript) API provides a number of convenient methods to get information about the system, the current logged in user, etc.
addErrorMessage
Adds an error message for the current session
addInfoMessage
Adds an info message for the current session
beginningOfLastMonth
Gets the date and time for the beginning of last month in UTC, adjusted for the timezone of the server
beginningOfLastWeek
Gets the date and time for the beginning of last week in UTC, adjusted for the timezone of the server
beginningOfLastYear
Gets the date and time for the beginning of last year in UTC, adjusted for the timezone of the server
beginningOfNextMonth
Gets the date and time for the beginning of next month in UTC, adjusted for the timezone of the server
beginningOfNextWeek
Gets the date and time for the beginning of next week in UTC, adjusted for the timezone of the server
beginningOfNextYear
Gets the date and time for the beginning of next year in UTC, adjusted for the timezone of the server
beginningOfThisMonth
Gets the date and time for the beginning of this month in UTC, adjusted for the timezone of the server
beginningOfThisQuarter
Gets the date and time for the beginning of this quarter in UTC, adjusted for the timezone of the server
beginningOfThisWeek
Gets the date and time for the beginning of this week in UTC, adjusted for the timezone of the server
beginningOfThisYear
Gets the date and time for the beginning of this year in UTC, adjusted for the timezone of the server
beginningOfWeek
Returns the (UTC) beginning of the specified week adjusted for the timezone of the current session
datePart
Returns a String of the form :interval,value,operator
daysAgo
Returns the (UTC) start of the day that was the specified number of days ago adjusted for the timezone of the server
daysAgoEnd
Returns the (UTC) end of the day that was the specified number of days ago adjusted for the timezone of the server
daysAgoStart
Returns the (UTC) start of the day that was the specified number of days ago adjusted for the timezone of the server
debug
Uses the debug level to log a message to the system log
endOfLastMonth
Gets the date and time for the end of last month in UTC, adjusted for the timezone of the server
endOfLastWeek
Returns the (UTC) end of last week adjusted for the timezone of the server
endOfLastYear
Gets the date and time for the end of last year in UTC, adjusted for the timezone of the server
endOfNextMonth
Gets the date and time for the end of next month in UTC, adjusted for the timezone of the server
endOfNextWeek
Returns the (UTC) end of next week adjusted for the timezone of the server
endOfNextYear
Gets the date and time for the end of next year in UTC, adjusted for the timezone of the server
endOfThisMonth
Gets the date and time for the end of this month in UTC, adjusted for the timezone of the server
endOfThisQuarter
Gets the date and time for the end of this quarter in UTC, adjusted for the timezone of the server
endOfThisWeek
Gets the date and time for the end of this week in UTC, adjusted for the timezone of the server
endOfThisYear
Gets the date and time for the end of this year in UTC, adjusted for the timezone of the server
endOfWeek
Returns the (UTC) end of the specified week adjusted for the timezone of the current session
error
Uses the error level to log a message to the system log
eventQueue
Queues an event for the event manager
generateGUID
Generates a GUID that can be used when a unique identifier is required
getCallerScopeName
Gets the caller scope name, or returns null if there is no caller
getCssCacheVersionString
Gets a string representing the cache version for a CSS file
getCurrentApplicationId
Gets the ID of current application, defined as a user preference and set by the application picker
getCurrentScopeName
Gets the name of the current scope
getDurationDate
Returns the date of the duration time after January 1
getMessage
Retrieves a message from UI messages. args is an optional paramter
getProperty
Retrieves a message from UI messages
getSession
Gets a reference to the current Glide session
getSessionID
Gets the GlideSession Session ID
getUrlOnStack
Gets the current URI for the session
getUser
Returns a reference to the GlideUser object for the current user
getUserDisplayName
Gets the display name of the current user (e.g., Abel Tuter, as opposed to abel.tuter)
getUserID
Gets the sys_id of the current user
getUserName
Gets the username, or User ID, of the current user (e.g., abel.tuter)
hasRole
Determines if the current user has the specified role
hoursAgo
number of hours ago
hoursAgoEnd
Returns the (UTC) end of the hour that was the specified number of hours ago adjusted for the timezone of the server
hoursAgoStart
Returns the (UTC) start of the hour that was the specified number of hours ago adjusted for the timezone of the server
include
Provides a safe way to call from the sandbox, allowing only trusted scripts to be included
info
Uses the info level to log a message to the system log
isDebugging
Determines if debugging is active for a specific scope
isInteractive
Checks if the current session is interactive
isLoggedIn
Determines if the current user is currently logged in
isMobile
Determines if the UI is running as mobile
minutesAgo
number of minutes ago
minutesAgoEnd
Returns the (UTC) end of the minute that was the specified number of minutes ago adjusted for the timezone of the serve
minutesAgoStart
Returns the (UTC) start of the minute that was the specified number of minutes ago adjusted for the timezone of the serve
monthsAgo
Returns the (UTC) start of the quarter that was the specified number of months ago adjusted for the timezone of the server
monthsAgoStart
Returns the (UTC) start of the quarter that was the specified number of months ago adjusted for the timezone of the server
nil
Queries an object and returns true if the object is null, undefined, or contains an empty string
quartersAgoEnd
Returns the (UTC) end of the quarter that was the specified number of quarters ago adjusted for the timezone of the server
quartersAgoStart
Returns the (UTC) start of the quarter that was the specified number of quarters ago adjusted for the timezone of the server
setRedirect
Set the redirect URI for this transaction. This determines the next page the user will see
tableExists
Determines if a database table exists
warn
Uses the warn level to log a message to the system log
yesterday
Returns (UTC) 24 hours ago adjusted for the timezone of the current session