Home
Function References
Reference for all built-in functions
Functions
I
isMonthStart

Deployment
Deploy and upgrade DolphinDB on premise or in the cloud
Database
Design and configure DolphinDB databases
Streaming
Publish, subscribe to, and process streaming data
Migration
Import and migrate data from various data sources to DolphinDB databases
Maintenance
Database maintenance and system management
Programming Guide
DolphinDB scripting language and SQL reference
Function References
Reference for all built-in functions
API & Connector
API in different languages for users to call DolphinDB from their programs
Plugins
Guidance on the use of plugins and plugin development for multiple application scenarios
Tutorials
Tutorials on database concepts and application scenarios
Release Notes
Release notes and compatibility changes for DolphinDB server, plugins and APIs

isMonthStart

Syntax

isMonthStart(X)

Arguments

X is a scalar/vector of type DATE, DATEHOUR, DATETIME, TIMESTAMP or NANOTIMESTAMP.

Details

Determine if each element in X is the first day of a month.

Examples

isMonthStart(2012.05.01);
// output
true

isMonthStart([2012.05.01,2012.05.02]);
// output
[true,false]

Related function: isMonthEnd