1 INTRODUCTION

2 BACKGROUND  
2.1 Preliminaries  
2.2 Loss Functions  
2.3 Benchmark Datasets  
2.4 Evaluation Protocol  

3 TEMPORAL KNOWLEDGE GRAPH COMPLETION  
3.1 Interpolation-based TKGCs  
3.2 Extrapolation-based TKGCs  

4 INTERPOLATION-BASED TKGCs  
4.1 Timestamps Dependent-based TKGCs  
4.2 Timestamps-specific Functions-based TKGCs  
4.3 Deep Learning-based TKGCs  

5 EXTRAPOLATION-BASED TKGCs  
5.1 Rule-based TKGCs  
5.2 Graph Neural Network-based TKGCs  
5.3 Meta Learning-based TKGCs  
5.4 Reinforcement Learning-based TKGCs  

6 APPLICATIONS  
6.1 Question Answering Systems  
6.2 Medical and Risk Analysis Systems  
6.3 Recommendation Systems  
6.4 Others  

7 FUTURE DIRECTIONS  
7.1 Multi-Modal Temporal Knowledge Graphs  
7.2 Inductive and Few-Shot Learning Settings  
7.3 Logical Query Answering via Temporal Conditions  
7.4 Unification with Large Language Models  
7.5 Interpretability Analysis  

8 CONCLUSION