Adventuring Time Advancement Initializer

Step 1. /give @p command_block
Step 2. Right click command block
Step 3. Paste command in
Step 4. Click Always Active then click Done

Command:

summon falling_block ~ ~1.5 ~ {Time:1,Block:redstone_block,Passengers:[{id:falling_block,Time:1,Block:activator_rail,Passengers:[{id:commandblock_minecart,Command:/tellraw @a {"text":"Adventuring Time Advancement by Onnowhere has been initialized!","color":"aqua"},TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/line_1,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/line_2,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/line_3,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/line_4,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/line_5,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/line_6,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/empty_slot_1,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/empty_slot_2,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/empty_slot_3,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/empty_slot_4,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/empty_slot_5,TrackOutput:0b},{id:commandblock_minecart,Command:/advancement grant @a minecraft:biomes/empty_slot_6,TrackOutput:0b},{id:commandblock_minecart,Command:setblock ~ ~1 ~ command_block 0 replace {Command:fill ~ ~-3 ~ ~ ~ ~ air,auto:1}},{id:commandblock_minecart,Command:kill @e[type=commandblock_minecart,r=1]}]}]}