lua-resty-datetime

Thread safe, lazy style, local datetime library

Environment

You can use this library under Windows or Linux, OpenResty or non-OpenResty.

Futures

A datetime object t can be described by a readable table t.table or a string t.string or a number t.number(timestamp). These attributes are lazy which means they're computed when needed, not when initialized.

Requirements

Same as openresty

Synopsis

    local datetime = require"lua.resty.datetime".datetime
    local timedelta = require"lua.resty.datetime".timedelta
    
    local function strfmt(t)
      return string.format('%04d-%02d-%02d %02d:%02d:%02d', 
          t.year,  t.month,  t.day, 
          t.hour or 0,  t.min or 0,  t.sec or 0)
    end
    
    local now_table = os.date('*t')
    local now_number = os.time(now_table)
    local now_string = strfmt(now_table)
    print('current localtime is', now_string, 'correspondent timestamp is', now_number)
    -- create a datetime object in three ways:
    local dtt = datetime.new(now_table) 
    local dtn = datetime.new(now_number)
    local dts = datetime.new(now_string)
    assert(dtt==dtn and dtn==dts, 'these three datetime object should be equal')
    local diff_days = 2
    local diff_hours = 1
    -- seconds = 2*24*3600 + 3600 = 176400
    local diff = timedelta.new{day=diff_days, hour=diff_hours}
    print(string.format('%s days and %s hour after   %s is %s(by table)', diff_days, diff_hours, dtt, dtt+diff))
    print(string.format('%s days and %s hour after   %s is %s(by number)', diff_days, diff_hours, dtn, dtn+diff))
    print(string.format('%s days and %s hour after   %s is %s(by string)', diff_days, diff_hours, dts, dts+diff))
    print(string.format('%s days and %s hour before  %s is %s(by table)', diff_days, diff_hours, dtt, dtt-diff))
    print(string.format('%s days and %s hour before  %s is %s(by number)', diff_days, diff_hours, dtn, dtn-diff))
    print(string.format('%s days and %s hour before  %s is %s(by string)', diff_days, diff_hours, dts, dts-diff))
    local dto = dtt + timedelta.new{hour=1, sec=1}
    print(string.format('%s is later   than %s by %s seconds', dto, dtt, (dto - dtt).total_seconds))
    local dto = dtt - timedelta.new{hour=1, sec=2}
    print(string.format('%s is earlier than %s by %s seconds', dto, dtt, (dtt - dto).total_seconds))